In a move which will, for the first time, bring on a woman on to the Facebook board, the social networking company revealed in a Monday announcement that its second-ranking executive, Chief Operating Officer Sheryl Sandberg, will become a board director.

42-year-old Sandberg - who is a married woman with two children - was named the eighth member of the Facebook board on Monday, with the company bringing on the high-profile woman executive to diversify its board and counter the criticism that its board was an all-male board.

With Sandberg's appointment as the director of the Facebook board coming amid intensified attempts to increase the number of women on American corporate boards, the social network's CEO Mark Zuckerberg said that Sandberg was his "partner" in running the company, and that had been "central to our growth and success over the years."

It was in 2008 that Sandberg left Google to join Facebook as its chief operating officer. Ever since her appointment at Facebook, she has been contributing greatly to help build the company's online ad business. She was also deeply involved in Facebook's recent initial public offering.

About her board appointment and her stint at Facebook, Sandberg said in a statement: "I feel fortunate to be part of a company that is having such a profound impact in the world."