(Corrects to remove reference to the New Hampshire’s bill needing governor’s signature to become law, 7th paragraph)

BOSTON (Reuters) - Maine’s senate passed a bill on Thursday that could make the northeastern U.S. state the fifth in the country to allow gay marriage, but the lower chamber and governor have yet to approve it.

The legislation, which will go to a vote in the state House of Representatives next week, seeks to redefine marriage as the legal union of two people rather than between a man and a women. It passed the senate by a 20-15 margin.

Maine Governor John Baldacci once opposed gay marriage, but said earlier in April he is keeping an open mind on the issue.

Approval in the Democratic-controlled senate of the rural state of 1.3 million people underlines a concerted push for same-sex marriage recognition in New England’s six states by gay and lesbian advocates.

Gay & Lesbian Advocates & Defenders, a group of lawyers who led the legal fight for same-sex marriage in Massachusetts and Connecticut, has set a target of bringing same-sex marriage to all New England states by 2012.

In November, Connecticut became the second state to allow legal same-sex weddings after neighboring Massachusetts’ top court ruled in 2003 that a ban on gay marriage was unconstitutional, paving the way for the first same-sex marriages in the United States the following year.

In a single week in April, Iowa and Vermont also legalized same sex marriage. And on Wednesday, New Hampshire’s state senate approved a gay marriage bill, about a month after its House approved it. It’s unclear whether New Hampshire Governor John Lynch will veto the legislation.

“With progress in New Hampshire and a win in Vermont, winning in Maine could put us only one state away from our goal,” Lee Swislow, executive director of Gay & Lesbian Advocates & Defenders, said in a statement.

Gay marriage legislation has yet to advance in Rhode Island.

Some economists say carving out an economic niche for gay and lesbian weddings -- and the spending that comes with them -- makes sense at a time same-sex marriage has stalled in California and a recession is deepening.