Thu May 31, 2007 7:10pm EDT

By Jill Serjeant

LOS ANGELES (Reuters) - The popular online dating service eHarmony was sued on Thursday for refusing to offer its services to gays, lesbians and bisexuals.

A lawsuit alleging discrimination based on sexual orientation was filed in Los Angeles Superior Court on behalf of Linda Carlson, who was denied access to eHarmony because she is gay.

Lawyers bringing the action said they believed it was the first lawsuit of its kind against eHarmony, which has long rankled the gay community with its failure to offer a "men seeking men" or "women seeking women" option.

They were seeking to make it a class action lawsuit on behalf of gays and lesbians excluded from the dating service.

eHarmony was founded in 2000 by evangelical Christian Dr. Neil Clark Warren and had strong early ties with the influential religious conservative group Focus on the Family.

It has more than 12 million registered users, and heavy television advertising has made it one of the nation's biggest Internet dating sites.

The company said the allegations of discrimination against gays were false and reckless.

"The research that eHarmony has developed, through years of research, to match couples has been based on traits and personality patterns of successful heterosexual marriages," it said in a statement.

"Nothing precludes us from providing same-sex matching in the future. It's just not a service we offer now based upon the research we have conducted," eHarmony added.

According to the lawsuit, Carlson, who lives in the San Francisco Bay area, tried to use the site's dating services in February 2007. When she was denied access, she wrote to eHarmony saying that its anti-gay policy was discriminatory under California law but the company refused to change it.

"Such outright discrimination is hurtful and disappointing for a business open to the public in this day and age," she said.

Carlson's lawyer Todd Schneider said the lawsuit was "about changing the landscape and making a statement out there that gay people, just like heterosexuals, have the right and desire to meet other people with whom they can fall in love."

Carlson's lawyers expect a significant number of gays and lesbians to join the class action, which seeks to force eHarmony to end its policy as well as unspecified damages for those denied eHarmony services based on their sexual orientation.