PORTLAND, Maine — ­Supporters of a ballot initiative to legalize same-sex marriage have raised about 25 times more money than opposition groups, according to finance ­reports filed with the state.

The reports show that political action committees in favor of November’s state referendum seeking to legalize same-sex marriage have raised nearly $1.2 million. The lead PAC, Mainers United for Marriage, has raised about $1.1 million.