(Adds attorney general's appeal, Boulder ruling)
DENVER, July 23 A federal judge ruled on Wednesday that Colorado's ban on same-sex marriage was unconstitutional, but stayed his ruling until the issue is decided by a higher court.
U.S. District Judge Raymond Moore found in favor of six same-sex couples who filed a lawsuit challenging the state's 2006 constitutional amendment that defined marriage as a union between one man and one woman.
Moore's 12-page ruling was the latest in a series of decisions by state and federal judges who have struck down state bans on gay marriage and then put their rulings on hold pending appeal.
Moore stayed his decision until Aug. 25.
Colorado Attorney General John Suthers said he was gratified the judge agreed that additional litigation in that court would be wasteful, since the U.S. Supreme Court has been asked to hear an appeal in neighboring Utah's case.
The Colorado law's status "will be decided by the Supreme Court's decision," Suthers, a Republican, said in a statement. His office later filed an appeal against Wednesday's decision with the 10th U.S. Circuit Court of Appeals.
Mari Newman, an attorney for the same-sex couples, said the attorney general's position was the only thing standing in the way of marriage equality for everyone in the state.
"It is time for him to back down from this losing battle and allow Colorado to treat all of its families with equality and dignity," Newman said.
Emboldened by a landmark U.S. appeals court ruling in June that found in favor of gay marriage in neighboring Utah and which was itself put on hold, three county clerks in Colorado had begun issuing marriage licenses despite a state ban on gay nuptials.
Colorado's Supreme Court last week ordered the Denver County clerk to stop issuing licenses to same-sex couples pending the resolution of an appeal by the state attorney general.
Denver County Clerk Debra Johnson began handing out licenses to gay couples on July 10, hours after a state judge backed a clerk in Boulder, Hillary Hall, who has issued more than 150 licenses since late June.
Johnson took to Twitter to praise Moore's ruling, saying it "moved our nation even closer to the ultimate victory at hand: every couple treated equally under law. #COProud"
Separately in Boulder on Wednesday, a state judge denied for a second time a motion by Suthers to halt the clerk's practice of handing out the permits to gay couples.
Boulder County District Court Judge Andrew Hartman said the state had offered no additional proof since his ruling two weeks ago that the licenses which Hall issues have "caused any harm to the state whatsoever, let alone irreparable harm."
"We are very pleased with the ruling and will continue issuing licenses," Hall said in a statement.
The county clerk in Colorado's Pueblo county, who issued nearly three dozen same-sex marriage licenses, agreed "reluctantly" this week to the state's request that he stop. (Reporting by Daniel Wallis; Additional reporting by Keith Coffman; Editing by Sandra Maler and Peter Cooney)