Mayor Michael Bloomberg is trying to raise $1 million to support same-sex marriage campaigns.
On Monday, Bloomberg said he's pledged $250,000 to a campaign in Washington State, $125,000 to one in Maine and another $125,000 to fight anti-same sex marriage legislation in Minnesota.
In early October, he gave $250,000 to a Maryland group that supports legalizing same-sex marriage in that state.
In a statement, the mayor said he is "proud to stand with supporters of marriage equality around the country this November."
The mayor announced last week that he is starting a SuperPAC to promote same-sex marriage initiatives as well as moderate candidates who share his support for gun control and education reform.
He is planning to spend more than $10 million on the effort this fall.