A historic effort to legalize same-sex marriage in Maryland is over for the year after the House of Delegates ended debate on Friday without taking a vote.

Instead of approving or rejecting the legislation, as expected, the House moved it backward - returning it to the committee that nearly killed it last week. House Speaker Michael E. Busch said the chamber won't entertain it again during the 2011 session, which concludes next month.

"This was a huge defeat for same-sex marriage," said Brian Brown, director of the National Organization for Marriage, which opposed the effort.

Advocates had believed that this year presented the best opportunity yet for gay marriage. While the effort ended in defeat, they could claim progress: Legislation that had never before been voted out of committee made it all the way through the Senate and onto the House floor.

Leaders say they "fully expect" the House of Delegates to take it up again next year.

"We took another step down a very long road, and we're going to continue to fight," said Del. Luke Clippinger. The Baltimore Democrat is one of eight openly gay Maryland lawmakers - one of whom came out to colleagues on the House floor Friday.

The legislation would have repealed state law defining marriage as the union of a man and a woman. It would have allowed the state to begin issuing marriage licenses to gay couples, but would not have required religious groups to perform same-sex ceremonies.

Gov. Martin O'Malley, who had said he would sign the bill but only recently began personally urging lawmakers to pass it, expressed disappointment Friday.

"I would have hoped we could have resolved this issue," he said.

Thousands of Marylanders deluged lawmakers with phone calls, e-mails and visits as gay marriage was debated, an outpouring veteran lawmakers said they had never seen.

Dozens of citizens on both sides of the issue piled into the State House on Friday to watch delegates make impassioned speeches before sending the legislation back to the House Judiciary Committee.

Advocates described the outcome as "heartbreaking," while opponents saw it as a sign that supporters overestimated Marylanders' comfort level with gay marriage.

"I'm reeling," said Ruth Siegel, a Silver Spring woman in a 12-year relationship with a woman. "This is a losing battle for them because you can't continue to oppress people forever."

Pastor Joel Peebles of Jericho City of Praise in Landover watched the debate from the gallery.

"Our objective was not to be against any group of people," he said, calling the House decision "a major benefit to our children and their children."

Had a vote been taken, House leaders said, the legislation would have come within a delegate or two of passage. Advocates believe they were a single vote shy.

"The vote would have been very close on the floor, make no mistake about it," said Busch, who supports same-sex marriage.

By moving the bill back into committee rather than taking a final vote, the 141 delegates avoided putting their positions on the record.

The decision angered observers on both sides, who said they wanted to see where each lawmaker stood.