• by Gavin O'Malley , Staff Writer @mp_gavin, October 16, 2012

Yahoo has hired Henrique De Castro -- a top sales executive at Google -- as its new COO, according to a regulatory filings released Monday.

“This is Mayer’s first big hire at Yahoo, having added only lower-level or less well-known execs to her stable of talent since she was appointed,” AllThingsD reports.

Including De Castro’s salary and stock grants, “The move could cost Yahoo more than $60 million,” writes CNet, citing the regulatory filing.

“This one is a doozy,” VentureBeat writes of the new hire. “He’ll have wide oversight of Yahoo’s business categories: sales, operations, media, and business development.”

“It’s a major role,” Marketing Land assures.

The job also represents a major challenge for De Castro as Yahoo “has been struggling to reverse a steady decline in its advertising business,” MercuryNews.com notes.

“Luring advertisers back to Yahoo is a top priority for the company,” according to The New York Times Bits blog. “Yahoo was once the biggest seller of display ads in the United States, but ceded that crown to Facebook and Google last year.”

“De Castro was previously vice president of Google's worldwide Partner Business Solutions group, where he was responsible for advertising platforms and services for Google's publisher and commerce partners,” VatorNews reminds us. “Before that, he led Google's media, mobile and platforms organization.”