Mayer Tells Ad Sales Staff That New COO De Castro Will Start in Mid-November

Yahoo CEO Marissa Mayer just told the company’s advertising sales staff that new COO Henrique De Castro will start around November 12, which clears up a big musical-chairs issue related to the departure of Chief Revenue Officer Michael Barrett.

Mayer had informed some managers at the Silicon Valley Internet giant earlier today that Barrett would be leaving, which she confirmed on a call that just took place.

Although he is essentially checked out, said sources, Barrett will stay on until mid-November when De Castro will start. Yahoo had said earlier this week that the Google exec might not be able to start work at Yahoo until early 2013, which the company said was related to his employment at the search giant.

It seems as if that problem is now resolved, with Google not giving Mayer — also a former top Googler — a hard time for poaching De Castro. He was in charge of publisher partnerships there.

That’s good news, since Yahoo’s sales staff has needed leadership since Mayer joined in July. Barrett had said publicly he was staying after she was hired, but had, in fact, been trying to depart. Also a former Googler, he had been hired by former interim CEO Ross Levinsohn.

According to numerous sources, Mayer has focused mostly on engineering and cultural issues at Yahoo so far, with the sales staff waiting to see what her plans to revive that business are.

Yahoo has been actively looking at ad tech companies to acquire, such as PubMatic and Rubicon Project, working with several investment bankers.

That will now fall to De Castro, who will now be the de facto sales leader at Yahoo, although he is likely to hire more senior execs to help him turn around Yahoo’s various ad businesses.

In the call, Mayer also told staff that De Castro will have oversight over media at Yahoo and that there would be a big effort going forward around programmatic selling and buying of ads.