15 months=$58 million for Yahoo's de Castro

Henrique de Castro's 15 months as Yahoo's chief operating officer may have ended on a sour note, but it was sweetened by a severance package worth nearly $58 million.

All but about $1 million of de Castro's severance was based on the value of his equity award in Yahoo, whose shares began appreciating after former Google colleague Marissa Mayer joined the company in July 2012.

De Castro became Mayer's first big hire just four months later. But in a letter to employees following de Castro's Jan. 16 ouster, Mayer said she "made the difficult decision" that he should leave.

His exit package outpaced Mayer's 2013 compensation, valued at $24.9 million. She gained an additional $21.2 million from vested shares, Yahoo said in a preliminary proxy filing Wednesday.

De Castro, a top Google sales exec, was hired to revive Yahoo advertising.

In defense of his hiring and sign-on package, Yahoo said its board of directors believed de Castro "had a unique set of highly valuable skills and experiences that would be key to returning the company to long-term growth and success and would best serve long-term shareholder interests."

Yahoo earlier rationalized the "significant compensation value" of de Castro's employment contract due to the potential payouts he forfeited to leave Google. His Yahoo severance included "negotiated protection'' in the event he was terminated, the company said.

Yahoo said de Castro's exit package would have been far smaller if not for the sharp gains in Yahoo's share price, which boosted the value of de Castro's holdings to nearly $57 million from $17 million.

Much of Yahoo's maket value increase, however, has had less to do with management moves than the soaring value of the company's 24% stake in Alibaba. The Chinese e-commerce giant is planning an initial public stock offering that could value the company at $200 billion.

De Castro's high-priced, short-lived tenure has already come under fire.

Last month, shareholders filed suit against Yahoo directors and de Castro, alleging that the board wasted corporate assets and breached its fiduciary duty by failing to understand how much compensation de Castro was entitled to. The company says it will try to have the case tossed.

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