The deal announced Tuesday gives Francoeur a raise of more than $1.6 million.
Francoeur hit .311 with 20 doubles, 10 home runs and 41 RBIs in 75 games with the Mets. He was acquired from Atlanta on July 10 for outfielder Ryan Church. Francoeur batted .280 overall with 15 homers and 76 RBIs last year, when he made $3,375,000.
He is eligible for free agency after the 2011 season.