Oliver Perez is staying with the Mets. Photo by AP

Free agent lefthander Oliver Perez has agreed to a $36-million, three-year deal to come back to the Mets, SI.com has learned.

The deal will be finalized after Perez passes a physical. No announcement is expected today.

The Mets ultimately decided to accede to Perez's wishes to be paid at least $12 million a year, but team executives felt good about the fact they kept it to a three-year deal. The Mets were originally thinking about $30 million for three years before boosting it to $33 million and ultimately to the final number. The deal was agreed to on Saturday night after months of haggling. Even though Perez had explored longer deals, signing a three-year contract could be to his advantage because it will allow him to be back on the free-agent market at age 30.

Both sides also agree that Perez has only begun to fulfill his potential after going 10-7 with a 4.22 ERA last year following a 15-10 season in 2007. He has performed superbly against the Phillies, Braves and Yankees while struggling against the Giants, Padres and Nationals, which has earned him a reputation as an inconsistent pitcher. The talent is obviously there, however.

Perez badly wanted to return to New York, where he resurrected his career after he struggled mightily in Pittsburgh. The Mets believed he had another, more lucrative offer, but it isn't known what other teams were in the bidding.

The Mets' main fallback option was veteran left-hander Randy Wolf, who appears to have a decent chance to return to the Dodgers, for whom he pitched in 2007. Mets people much preferred the potential of Perez even though they had to give him a longer contract. Perez may prove to be the final pitcher to receive a multiyear deal in an awful market. Originally, he sought a five-year deal.

FoxSports.com first reported earlier this afternoon that the two sides were closer to a deal.