Bryer courted co-founder Mark Zuckerberg in Facebook's early days and eventually got him to agree to take a $12.7 million investment that valued the company at $93 million. What a bet that turned out to be -- for Breyer and his firm. Accel sold $2.1 billion worth of shares into Facebook's IPO last May. Last October, Breyer personally cashed in more than $81.1 million in Facebook shares, according to a SEC filing.
Breyer, who also serves on boards of Dell and Wal-Mart, will serve as director until Facebook's annual meeting on June 11.
In a statement emailed to CNET, Breyer confirmed that he is stepping down to focus on other responsibilities, including his recent election to the Harvard University Corporation Board.
Breyer said it was a "genuine honor" to serve as a Facebook investor and board member.
A Facebook spokesperson told CNET that it will continue to have a strong relationship with Breyer going forward. "Jim made many, many important contributions during his long tenure on the board and we were well-served by his presence."
"I will leave the board knowing that Facebook is a global Internet leader with exceptional leadership within the company and on the board," Breyer added.