The New York Daily News’ Adam Rubin on Al Leiter’s future plans.

Al Leiter filed for free agency Friday, though the veteran lefty is expected to return to the Mets.

The Mets have until Nov. 15 to decline Leiter’s $10 million option for 2005, and ultimately will pay him a $2 million buyout instead.

They already are believed to have offered a $4 million base salary to Leiter for next season, which he would collect in addition to the buyout money, and he could earn more from performance-based incentives. Team insiders have expressed confidence a deal will be reached in the next week, but agent Randy Hendricks said yesterday: “We are filing so Al can become a free agent if the option is not exercised. We have never been close to a deal.”

Leiter, 39, also could pursue a one-year contract with the Yankees or Phillies, but it might not be the best career move. He plans to retire after next season and should benefit from remaining with the Mets; the organization plans to launch its regional television network for the 2006 season, and Leiter has worked playoff broadcasts for ESPN and Fox.

Leiter went 10-8 with a 3.21 ERA last season, though he logged only 173-2/3 innings because of high pitch counts, taxing the bullpen.

“It’s a formality,” said Mets GM Omar Minaya. “I spoke to his agent today. We’re in negotiations and we’re hopeful that Al will be back with us next year.”