State Assemblyman Michael Benjamin on Monday closed the door on the possibility of challenging Rep. José Serrano in September’s Democratic primary.

There have been rumors for months that Benjamin, 52, was thinking about running against Serrano in the 16th district, and those grew louder a month ago after Benjamin announced that he would not seek a fifth term in Albany. But Benjamin told the newspaper City Hall on Monday that while he is still interested in pursuing higher office, he has decided to wait until 2012.

“There are those who might not be supportive of the incumbent Congressman, but he’s not a priority of theirs to unseat,” Benjamin said. “We’ll give it a go after reapportionment. … You never know what doors will open or why.”

Under several Empire State redistricting scenarios, the Bronx, which Serrano has represented since winning a special election in 1990, could get a second majority-minority Congressional seat. The rest of the borough is represented in Congress by white Members: Rep. Eliot Engel (D), whose district also includes portions of Westchester and Rockland counties, and Rep. Joe Crowley (D), whose district includes portions of Queens. Another redistricting scenario has the Harlem-based district of Rep. Charlie Rangel (D) extended north to the Bronx in 2012.

Serrano, 66, has never faced a tough re-election battle.