SAN DIEGO – All-Star catcher Mike Piazza agreed yesterday to a $2 million, one-year contract with the San Diego Padres, giving the defending NL West champions a marquee player they think can still contribute.

Piazza, 37, had been interested in signing a free-agent deal with an AL team to become a designated hitter. Instead, he’ll stay in the NL and return to the West Coast for the first time since the Los Angeles Dodgers traded him to Florida in 1998.

The 12-time All-Star holds the major league record for most career home runs by a catcher (374). He has 397 homers overall, and is a career .311 hitter.

The deal is expected to be announced today. It includes a mutual option for 2007 at $8 million.

“The Padres told Mike that he could pretty much catch as much as he wanted to,” Piazza’s agent, Dan Lozano, said.

Piazza is hoping to catch about 90-100 games this season, along with playing some first base and being the designated hitter in interleague games.

Piazza became a free agent after last season, when he hit .251 with 19 homers and 62 RBI in 113 games for the Mets. It was his lowest batting average since he hit .232 in 69 at-bats with the Dodgers in 1992, his first season in the big leagues.

Still, his 19 homers would have led the power-poor Padres. Ryan Klesko hit 18 for San Diego, which struggled to the division title before being swept out of the playoffs by the St. Louis Cardinals.

The Padres got into the Piazza mix in December, around the time of the winter meetings. They held off making a firm offer because there was talk Piazza might have been headed for the New York Yankees, who have Bernie Williams and other players as possible DHs.

The Padres made the offer Saturday night and Piazza accepted yesterday.

Piazza reportedly had also considered playing for the Phillies. He grew up near Philadelphia.

Padres general manager Kevin Towers wasn’t available for comment yesterday.

Speaking last Friday, Towers said Piazza wanted to play “with a competitive team in a desirable city. I think that his experience when he was with L.A. was a good one. He’s very popular out here and is familiar with the area. We’d like to think San Diego is a desirable city and that we’re a competitive ballclub.”

Piazza was slowed by injuries the past three years and has long had trouble throwing.

He was acquired by the Mets in a trade with Florida in May 1998, eight days after he was shipped from the Dodgers to the Marlins in a blockbuster deal that also included Gary Sheffield, Bobby Bonilla, Charles Johnson, and Todd Zeile.

Piazza led the Mets to the 2000 World Series, which they lost to the crosstown Yankees in five games.

The Padres will have to move a player off their 40-man roster before signing Piazza.