* Gay marriages should be allowed, state's top lawyer says
* Request follows White House shift toward gay rights
* Same-sex weddings on hold in California pending appeal
SAN FRANCISCO, March 1 (Reuters) - California's attorney general urged a U.S. appeals court on Tuesday to permit gay marriages while it considers whether to overturn the state's ban on same-sex weddings.
The move follows a decision last week by U.S. President Barack Obama's administration that it would no longer defend the 15-year-old U.S. law defining marriage as only between a man and a woman, a major policy shift in favor of gay rights.
Attorney General Kamala Harris, in arguments filed with the 9th U.S. Circuit Court of Appeals, asked the court to dismiss its order prohibiting gay marriages in the most populous U.S. state while a lawsuit over California's ban unfolds.
California voters had approved the ban in 2008 by endorsing a statewide initiative known as Proposition 8. But last year U.S. District Judge Vaughn Walker in San Francisco ruled it was unconstitutional.
The decision was put on hold pending appeal.
Meanwhile, the federal appeals court has asked California's Supreme Court to consider whether supporters of Proposition 8 have standing to defend it after state officials declined to do so, a process that may take until the end of the year.
Harris said it is unlikely an appeal will succeed in overturning Walker's decision that Proposition 8 is unconstitutional.
"There is no injury that the proponents of Proposition 8 will suffer if same-sex couples are permitted to enter into civil marriages in California," Harris added.
The hot-button issue of same-sex marriage has been the focus of many judicial and political battles across the country. Gay marriage has only been legalized in the District of Columbia and five of the 50 states -- Connecticut, Massachusetts, Iowa, New Hampshire and Vermont, although some states do permit same-sex civil unions.
Reporting by Jim Christie; Editing by Eric Walsh