By Ian Simpson
(Reuters) - A U.S. appeals court on Monday struck down Virginia's ban on same-sex marriage as unconstitutional, the latest in a string of court rulings across the country to back gay marriage.
A panel of the 4th U.S. Circuit Court of Appeals in Richmond, Virginia, ruled 2-1 to affirm a February ruling by a federal judge who struck down the state ban as unconstitutional.
Judges Roger Gregory and Henry Floyd wrote that barring gay couples from marrying violated rights to due process and equal protection under the U.S. Constitution's 14th Amendment.
"Denying same-sex couples this choice prohibits them from participating fully in our society, which is precisely the type of segregation that the Fourteenth Amendment cannot countenance," they said.
Fifty-seven percent of voters approved Virginia's constitutional ban on gay marriage in 2006.
The panel's decision takes effect in 21 days, but could be stayed if the defendants ask the full court of appeals to review it.
In his dissent, Judge Paul Niemeyer said there was no fundamental right to gay marriage. Defining marriage is best left up to the states, he said.
Virginia Attorney General Mark Herring, a Democrat who refused to defend the ban in court, said in a statement the ruling marked "a joyous and historic day for our Commonwealth."
But Byron Babione, an attorney for the Alliance Defending Freedom that represented a county clerk sued over the marriage ban, said the clerk was considering an appeal. The Supreme Court ultimately must rule whether states can set rules for marriage, he said.
Monday's ruling could also affect gay marriage bans in other 4th Circuit states - North Carolina, South Carolina and West Virginia.
North Carolina Attorney General Roy Cooper, a Democrat, told reporters his office would stop defending the state's gay marriage ban in four cases challenging it.
Approval of same-sex marriage has gained speed since the U.S. Supreme Court ruled in June 2013 that legally married same-sex couples were eligible for federal benefits.
Since the ruling, all the roughly 20 federal and state courts that have addressed the issue have ruled against state bans. Nineteen states and the District of Columbia allow same-sex marriage.
The 10th U.S. Circuit Court of Appeals struck down gay marriage bans in Utah and Oklahoma in June.
Appeals are headed toward the Supreme Court, which could take up a gay marriage case in the term that begins this October.
(Reporting by Ian Simpson in Washington; Additional reporting by Joan Biskupic and Lawrence Hurley; Editing by Bill Trott, Doina Chiacu and Peter Cooney)