By Dan Levine

SAN FRANCISCO (Reuters) - A California ban on controversial therapy designed to reverse homosexuality in children cannot be enforced while the constitutionality of the law is being challenged in court, a U.S. appeals court ruled late on Friday.

California's Democratic Governor Jerry Brown signed the ban into law in September, making the nation's most populous state the first to ban so-called conversion therapy among youths.

Earlier this month U.S. District Court Judge Kimberly Mueller denied an injunction request against the law filed by the National Association for Research and Therapy of Homosexuality and the American Association of Christian Counselors, as well as unnamed individuals who sued shortly after the law was signed.

Those groups appealed Mueller's ruling. In a brief order on Friday, the 9th U.S. Circuit Court of Appeals in San Francisco put the law on hold during the appeals process. The law had been scheduled to take effect January 1.

"California was correct to outlaw this unsound and harmful practice, and the Attorney General will vigorously defend this law," said Lynda Gledhill, a spokeswoman for California Attorney General Kamala Harris.

In a press release on Friday, Liberty Counsel attorneys who represent the plaintiffs praised the order.

"The minors we represent have not and do not want to act on same-sex attractions, nor do they want to engage in such behavior," said lead counsel Matthew Staver.

"They are greatly benefiting from counseling." Continued...