Silicon Valley’s Silver Lake and DST Global of Russia, as well as Chinese private equity firm Yunfeng Capital, are leading a $1.6 billion tender offer for privately held employee and shareholder stock of China’s Alibaba Group, according to sources close to the situation.

Yunfeng, by the way, was co-founded by Alibaba Chairman and CEO Jack Ma, as well as other prominent Chinese entrepreneurs.

Along with DST, Silver Lake and Yunfeng, Singapore-based investment firm Temasek is also participating in the tender offer as an investor, but in a smaller way.

The deal, which has been discussed for some time, was signed earlier today and will be presented to its employees in an internal company blog, which will be in Chinese.

To get around persistent foreign ownership issues in China, sources said, DST and Silver Lake are ceding voting control of their stakes to Alibaba management.

If the tender is fully subscribed, that would mean a stake of just under five percent for the group, sources said, and it gives Alibaba a $32 billion enterprise valuation.

The impetus for the tender offer, which begins today, appears to be trying to address a cash-out, paper-rich issue for Alibaba employees.

There are no active secondary private markets in China, as is the case for tech start-ups in the U.S., and there is also no IPO in the foreseeable future for Alibaba. Thus, management has been looking for a way to give its employees and also other shareholders some liquidity.

This tender offer is not a capital raise by Alibaba and is only aimed at eligible employees and shareholders. The purchase of the Alibaba shares is expected to close before the end of December.

It will be done via a special investment vehicle, specifically aimed at this purchase, that includes a spate of investors. Giant Interactive Group, a Chinese online game developer, for example, said it had committed $50 million to the fund.

It’s not clear what the implications are for Alibaba’s biggest shareholder, Yahoo, which sources said is not selling shares in the tender offer. Yahoo’s fully diluted Alibaba 39 percent stake is now worth $12.5 billion in the deal.

That’s discounted due to tax issues and also the inability of the Silicon Valley Internet giant to sell its Alibaba shares.

In other words, investors will likely welcome this higher valuation, but realize a public offering is farther away than ever.

But it is interesting in that it clearly shows a strong relationship between DST and Silver Lake, which have jointly been mulling a possible bid for Yahoo along with Silicon Valley venture firm Andreessen Horowitz, as I previously reported.

Some will speculate that Silver Lake and DST now have an in with Alibaba, which is important, since a large slug of Yahoo’s market valuation is due to its Alibaba and also Yahoo Japan! assets.

If Yahoo is sold, of course, the disposition of the Alibaba asset is an important part of the deal.

More to come, including the implications for Ma, who has been under siege of late around his spinning out of Alibaba’s Alipay payments service and the noisy battle that later ensued with Yahoo. Yahoo and Alibaba, as well as its other large shareholder, Japan’s SoftBank, settled that dispute earlier this summer.

His involvement in Yunfeng, which is buying the company’s shares in a special fund that Ma is not in, will likely attract some scrutiny, anyway.

Sources said Ma is a minority investor in Yunfeng itself, has no control rights and is not a director. In addition, Yunfeng has no relationship with Alibaba.

In another interesting twist, Alibaba rival Tencent has close ties with DST’s Internet affiliate that used to share the same name, having invested $300 million last year in the affiliate that holds major Russian Internet properties.

Whether or not to sell any of their shares in Twitter is the big decision facing stakeholders of the microblogging service right now, as the second $400 million part of the company’s recent funding by Russia’s DST Global is completed in the next several weeks.

That includes everyone from early angel investors to those who bought it on the secondary markets to Twitter’s 600 employees, all of whom can sell a portion — up to 20 percent, sources said — of their holdings.

It’s all part of a recent $800 million mega-funding by Twitter, valuing the San Francisco company at $8.4 billion.

While $400 million went to Twitter, the second tranche of $400 million of the total was targeted to cash out current investors and also employees of the company.

Current investors include Benchmark Capital, Union Square Ventures, Spark Capital and several other venture firms, as well as a spate of prominent angel investors, such as Ron Conway.

Whether DST — as well as other smaller buyers, including early Twitter investor Chris Sacca and T. Rowe Price, according to the tender offer — gets them and others to sell enough shares is the big question, especially since few want to get caught in what one shareholder called the “Facebook idiot box.”

That would be referring to those who sold their investments in Facebook two years ago, when the social networking giant allowed its employees to sell 20 percent of their stakes to DST.

The financing was part of a $100 million add-on to a $200 million investment in the social networking company by the aggressive Russian investor.

At the time, the tender offer valued Facebook at $6.5 billion for the common stock, or $14.77 a share.

Of course, Facebook is worth upward of more than 10 times that now. Oops!

That’s why high-profile Silicon Valley venture firm Andreessen Horowitz, for example, is not selling out any of the shares it bought earlier this year in an $80 million transaction in private secondary markets.

Reasons to sell, of course, are also compelling.

Some investors might want to lock in upside, especially if they think the latest valuation is too high.

For venture capitalists in the company, some might want to return a win to their limited partners, while Twitter employees might want to put a down payment on a house after years of toiling in the start-up.

Others might also be worried about Twitter’s prospects going forward and might determine that the recent round was the high point of its market value. Twitter has indeed struggled to find a sustainable and lucrative business model, focused on advertising.

In addition, although it has recently stabilized, others might worry about Twitter’s management changes over the last year, as co-founders Biz Stone and Evan Williams have departed. Twitter creator and other co-founder Jack Dorsey is now running the company’s product efforts, with CEO Dick Costolo (who looks a lot like that Woody Allen shot above from the classic movie, “Take the Money and Run”).

Then again, that was exactly the take on Facebook several years ago, so it is now a case on all sides of seller beware.

Twitter declined to comment and I have not heard back yet from DST about the status of the transaction.

Facebook is exploring permitting a tender offer up to $1 billion of its employee shares, after being approached by a number of big institutional investors about investing in the company, according to sources close to the situation.

The new approximate valuation? An eye-popping $60 billion, sources said, which is a significant increase to a recent $1.5 billion investment round by Goldman Sachs and its international clients that had pegged the social networking behemoth at a $50 billion valuation.

And the reason? Liquidity, allowing Facebook employees to monetize their privately held shares, since the company is not likely to have an IPO for at least a year.

That’s been a big issue for Facebook as it seeks to walk the ever dicier line between being a private company and becoming a public company.

And managing how its shares are dispersed is critical, especially with regulatory concerns about these private secondary markets increasing.

All the machinating is because Facebook has tried hard–via ever bigger funding rounds and ever larger valuations–to delay its IPO, in order to grow its massive 600-million user base away from scrutiny.

The move is not dissimilar to one that the Palo Alto, Calif.-based company did in mid-2009, when one of its major investors, DST, forked over $100 million for employee shares in a transaction that was in addition to a $200 million investment.

At that time, current and former employees of Facebook were able to sell up to 20 percent of their common shares at $14.77 per share at a $6.5 billion valuation.

If completed, the new tender offer would be at a share price almost 10 times that. But sources said interest is high among big institutional investors who want a piece of Facebook before its inevitable initial public offering.

It’s likely the deal will be split between two or more investors, sources added.

A Facebook spokesman declined to comment.

The latest wrinkle is part of a massive race to invest in the winners of Web 2.0, often via secondary market sales.

Silicon Valley venture firm Andreessen Horowitz, for example, confirmed it had bought $80 million in shares of Twitter, in a story first reported here.

That works out to $24 per share in cash for iPCS. This is a 34 percent premium over the company’s closing price of $17.88 per share on Friday, but perhaps a small price to pay for putting an end to the two iPCS lawsuits–one over Sprint’s acquisition of Virgin Mobile, the other over its investment in Wimax operator Clearwire.

As a result of the iPCS deal, Sprint (S) will no longer be required to divest its iDen network in certain iPCS (IPCS) territories, though iPCS had won a court ruling requiring Sprint to do so. Now, Sprint will not only keep those assets, it can peddle their services to some 700,000 iPCS customers in a territory that covers 81 markets in seven states.

Below, the official announcement:

Sprint Nextel to Acquire Wireless Affiliate iPCS, Inc.

More than 700,000 PCS Wireless Users and 270,000 Wholesale Customers to Become Sprint Direct Subscribers
Extends Company’s Direct Service Territory to an Additional 12.6 Million People
Sprint Ends Plan to Divest iDEN Network Assets in Certain Midwestern States Pending Transaction Close
OVERLAND PARK, Kan. & SCHAUMBURG, Ill.–(BUSINESS WIRE)–Oct. 19, 2009– Sprint Nextel Corp. (NYSE: S) and iPCS, Inc. (NASDAQ: IPCS) today announced an agreement for Sprint Nextel to acquire iPCS for approximately $831 million, including the assumption of $405 million of net debt. This transaction value represents 6.4x projected 2010 Adjusted Earnings Before Income, Taxes, and Depreciation (“Adjusted EBITDA”*). Sprint expects to achieve approximately $30 million of synergies annually in the transaction and expects the transaction to be free cash flow accretive to Sprint in 2010.

Under the terms of the agreement, Sprint Nextel will commence a cash tender offer to acquire all of iPCS’ outstanding common shares for $24.00 per share. This price per share represents a 34 percent premium to iPCS’ closing stock price as of October 16, 2009. The agreement also requires a minimum of a majority of the shares outstanding (on a fully-diluted basis) to be tendered in the offer. Following completion of the tender offer, any remaining shares of iPCS will be acquired in a cash merger at the same price per share. Shareholders with approximately 9.5 percent of the outstanding common shares of iPCS have already agreed to tender their shares pursuant to the tender offer and to vote their shares in favor of the merger.

The acquisition is subject to customary regulatory approvals and other customary closing conditions, and is expected to be completed either late in the fourth quarter of 2009 or early 2010. As part of the agreement, Sprint Nextel and iPCS will seek an immediate stay of all pending litigation between the parties with a final resolution to become effective upon closing of the acquisition.

As a result, Sprint will no longer be required to divest its iDEN network in certain iPCS territories and will terminate its previously announced divestiture process pending closing of the transaction.

iPCS’s services are sold under the Sprint brand name and in Sprint-branded stores. Because of the nearly seamless marketing and sales relationship between Sprint and iPCS, customers should not experience any change in their service as a result of this transaction.

“Acquiring iPCS brings added value to Sprint by expanding our direct customer base, growing our direct coverage area and simplifying our business operations,” said Dan Hesse, CEO of Sprint Nextel. “Customers in iPCS territory will see a seamless transition and continue to enjoy a superb customer experience.”

“We are very pleased to have reached this agreement with Sprint Nextel. Given the increasingly competitive landscape, we believe this is an opportune time to provide our shareholders with a liquidity event at a very attractive price. iPCS shareholders will receive a significant and immediate premium for their shares and our customers will continue to receive the same excellent service from the same dedicated people who provide that service today,” said Timothy M. Yager, president and CEO of iPCS. “We look forward to working with the Sprint Nextel team to ensure a smooth completion of the transaction and transition in the coming months.”

[UPDATED: With news that employees can sell up to 20 percent of their shares.]

According to sources close to the situation, current and former employees of Facebook are now going to be able to sell up to 20 percent of their common shares.

It is part of a $100 million add-on investment in the social networking company by the Russian investors who recently put $200 million into the company for preferred shares.

That investment a month ago by Digital Sky Technologies was valued at $10 billion, since those shares have various special rights, depending on what was negotiated.

The new tender offer by DST values the company at $6.5 billion for the common shares, or $14.77 a share. The last common share valuation of the company was around $4 billion.

The move has been expected for Facebook employees since DST made its first investment.

It will allow them to monetize shares, since the company is not likely to go public for at least a year or more.

Employees have 20 days to decide to take the offer or not and can only sell up to 20 percent of their stock–in other words, they cannot cash out completely.

“I can afford a down payment on a house now,” said one longtime employee, who is typical of many. “But not a really big house.”

But the top leadership of Facebook, such as CEO Mark Zuckerberg or COO Sheryl Sandberg, are not eligible to sell shares.

Facebook confirmed the DST investment, with a statement from Zuckerberg:

“While individuals must make their own decisions about participating in this program, I’m pleased that the price DST is offering is much greater than the price originally considered last fall. This is recognition of Facebook’s growth and progress towards making the world more open and connected.”

If fully accepted by those employees eligible, it will give DST 1.54 percent more of Facebook, for a total of 3.5 percent of the company.

That makes DST–based in London and Moscow–one of the bigger Facebook investors, with a stake larger than one owned by Microsoft (MSFT).

The software giant invested $250 million in Facebook for preferred shares in 2007, but the valuation was then $15 billion. That huge figure was due to a competing bid from archrival Google (GOOG) at the time.

In any case, neither DST nor Microsoft got a board seat or “special observer rights” in return for its money.

Here’s a video interview I did with one of DST’s top execs, Alexander Tamas, along with Sandberg, right after it made its first investment in May, while both were attending the seventh D: All Things Digital conference: