Yahoo! on Monday announced it had nabbed another key Google executive, naming Henrique de Castro as chief operating officer.

De Castro will report directly to chief executive Marissa Mayer, who came from Google in July to help turn around the struggling Internet pioneer.

"Henrique is an incredibly accomplished and rigorous business leader, and I'm personally excited to have him join Yahoo!'s strong leadership team," said Mayer.

"His operational experience in Internet advertising and his proven success in structuring and scaling global organizations make him the perfect fit for Yahoo! as we propel the business to its next phase of growth."

Mayer tweeted that Monday's announcement came on her "first full day back in the office" following just two weeks of maternity leave.

De Castro said in a statement that Yahoo! has a potential to use its "outstanding user experience and its massive reach to bring tremendous value to users, advertisers and partners."

"This is a pivotal point in Yahoo!'s history, and I believe strongly in the opportunity ahead," he said. "I can't wait to join Marissa and the team and get started."

De Castro was 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.

Prior to that, he led Google's media, mobile and platforms organization. He has also worked at Dell and the consulting firm McKinsey.

De Castro will join the company by January 22, "or as soon as he has satisfied his obligations to his current employer," Yahoo! said.

According to a regulatory filing, de Castro will receive an annual base salary of $600,000 and a one-time retention equity award. Some $18 million will be in the form of restricted stock units and another $18 million in performance-based stock options. He will get a $1 million bonus for leaving Google.

Yahoo! has been trying to reinvent itself since the once-flowering Internet search service found itself withering in Google's shadow.