SAN FRANCISCO — Facebook executive Sheryl Sandberg says she turned down entreaties to enter a no-poach pact with Google similar to those at issue in a massive class action targeting several of Silicon Valley’s largest tech companies.

Sandberg, who left Google Inc. in 2008 to become Facebook’s chief operating officer, said in a sworn statement that two senior Google executives subsequently approached her with concerns about Facebook’s hiring of Google employees. However, she declined to limit recruitment or hiring of Google employees and hasn’t authorized any such agreement since, according to the declaration.