Petrov leaves Man City for Bolton
Petrov became a free agent when his contract at Manchester City expired this month.
He will complete his move to the Reebok stadium when the transfer window opens on July 1.
The 31-year-old scored 12 goals in 72 appearances for City after signing for 4.7 million pounds from Atletico Madrid in 2007. He has won 77 caps for Bulgaria.