Yahoo COO departure marks major shakeup for Marissa Mayer's team

Well, that was quick.

Henrique de Castro is leaving his post as chief operating officer of Yahoo, effective tomorrow, January 16.

After murmurs surfaced in the tech press earlier in the day, the move was announced formally through an 8-K filing with the U.S. Securities and Exchange Commission on Wednesday afternoon.

According to the same filing, de Castro will receive the severance benefits provided for in his Employment Offer Letter from when he first signed on with Yahoo back in October 2012.

That would make him the most senior hire during Mayer's tenure since she joined the search company in July 2012.

It would also make for the most notable departure under her watch too. A reason for de Castro's departure has not been revealed.

The letter was finalized the following February.

The outgoing COO's offer letter is also on public record with the SEC, with the following note concerning his severance package:

In the case of a Cause termination of your employment by the Company or a voluntary resignation by you without Good Reason, all unvested RSUs and Stock Options shall be immediately forfeited. As used herein, a “Specified Percentage” shall mean (i) 25%, if your employment is terminated prior to the first anniversary of the applicable date of grant, (ii) 50%, if your employment is terminated on or after the first anniversary and prior to the second anniversary of the applicable date of grant, (iii) 75%, if your employment is terminated on or after the second anniversary and prior to the third anniversary of the applicable date of grant, and (iv) 100%, if your employment is terminated after the third anniversary of the applicable date of grant. In the event of any termination covered by Yahoo!’s change in control severance plans, the applicable provision of such plan then in effect shall apply, but any accelerated vesting for termination of your employment by you with Good Reason, due to your disability or as a result of your death, will only apply with respect to the Specified Percentage of the RSUs and Stock Options and not with respect to the entire grant amounts.

Being that de Castro has been with Yahoo for little more than a year, Item "ii" is the most important line in that excerpt determining how much he'll get to keep from his stock portfolio.

The Wall Street Journal is reporting that de Castro was promised with $38 million in restricted stock.

Much like Mayer, de Castro is a former Googler who lead global media and platforms for the Internet giant from 2006 up until his move to Yahoo. Prior posts include leadership roles at Dell and McKinsey & Company.