That disappointment, however, was tempered by strong auto sales that helped drive subscriber growth. Sirius added 373,064 net subscribers during the quarter, ending it with a new high of 20.6 million customers. That’s up 9 percent from 18.9 million a year earlier, and it likely would have been higher were it not for recent calamities in Japan.

“Consumers are buying cars again and demand for our product is strong,” CEO Mel Karmazin said in a statement. “Were it not for the OEM supply chain uncertainty resulting from the tragedy in Japan, we would be in a position to raise our subscriber guidance today.”

At $2.00, Sirius shares are up 4.71 percent as I write this.

Analysts had been calling for Sirius to break even in its fourth quarter on revenue of $740 million. Instead it reported a loss of $81.4 million, or two cents a share, on revenue of $735.9 million. The reason for the miss: An increase in operating expenses and $85.4 million in debt-extinguishment losses.

Unfortunate. Still, the company’s latest financials weren’t without some good news. Sirius added 328,789 new subscribers in the fourth quarter, up from 257,028 in the fourth quarter of 2009. And it ended 2010 with 20.2 million subscribers, 8 percent more than the 18.8 million it claimed at the end of 2009, and well above its target of 20.1 million.

That should be an easy thing to pull off, particularly if the company manages to renew its deal with Howard Stern, whose contract expires at the end of the year. But it hasn’t done that yet, according to Karmazin. “We had hoped that prior to this call we would have an update on the status of Howard Stern with Sirius XM,” he said this morning. “We do not have any update today, other than to say discussions continue.”

Just about this time a year ago, Sirius XM Radio was up a certain creek with nary a paddle in sight. Its shares were trading at around 35 cents, it was hemorrhaging money, and anemic car sales had just led it to post its first-ever decline in net subscriber additions. The company ended its June 2009 quarter with 18.6 million subscribers–up 3.5 percent from a year earlier but down 404,000 subscribers from the preceding quarter. And though it added 1,338,961 new customers, Sirius lost 1,743,383.

Which makes the satellite-radio operator’s announcement of a nice spike in subscribership today all the more sweet.

Sirius (SIRI) said this morning that it added 583,000 net subscribers in the second quarter, bringing total subscribership to 19,524,448–a new record. And with that as a backdrop, the company raised its forecast for net subscriber additions for the third time, boosting this year’s projected growth to 1.1 million subscribers from 750,000.

“Our subscriber results mark the best quarter of gross additions, deactivations and net additions since the merger of Sirius and XM in July 2008,” CEO Mel Karmazin said in a statement. “The strong execution in both adding subscribers and retaining them resulted in our record-high 19.5 million subscriber milestone, despite continued economic uncertainty. The further improvement in our guidance reflects the attractiveness of satellite radio but maintains a cautious outlook for continued improvement in the economy.”

Analysts polled by Thomson Reuters had expected the company to break even on revenue of $671 million. Sirius added 171,441 net subscribers during the period and reiterated its view that it expects to add more than 500,000 subscribers this year.

With quarterly net subscriber additions of 171,441, Sirius (SIRI) ended March with 18,944,199 subscribers. Quite an improvement over the year-ago quarter, when it lost 404,422 subscribers.

“Continued positive subscriber growth, double-digit growth in revenue, and a sharp focus on costs resulted in the highest quarterly adjusted operating income in the company’s history,” Sirius CEO Mel Karmazin said in a statement. “The continuing recovery of the automotive sector and expanding signs of increased consumer spending are encouraging signs for the company’s growth prospects.”

Still more good news for the company, which last week avoided delisting from Nasdaq. That said, at $1.14, Sirius shares are trading down 7.32 percent this morning. Evidently, the revenue miss didn’t go over too well with investors.

As of market close today, the company’s shares have traded above $1 for 10 straight days, putting it back in compliance with NASDAQ’s minimum bid requirement. As a result, the NASDAQ Listing Qualifications Panel hearing Sirius was to attend Thursday has been canceled and the company is no longer in danger of being booted to the Pink Sheets — not that it ever was, really.

More good news for Sirius whose shares were trading at a new 52-week high of $1.20 yesterday.

Why? Well, sentiment about the company and its prospects are clearly improving now that it has its finances in order. The unexpected increase in subscriber growth the company recently reported is obviously helping as well. Also presumably fueling the rally is increasing confidence that Howard Stern will stick with Sirius, rather than bail for terrestrial radio when his contract expires next year. Beyond that, I’m not entirely sure.

In any event, it seems there’s no longer a need for a reverse stock split to push Sirius above the $1 per share minimum for Nasdaq trading.