A settlement Wednesday between eHarmony Inc. and the New Jersey attorney general requires the online heterosexual dating service to also cater to homosexuals, raising questions about whether other services that target a niche clientele could be forced to expand their business models.

The settlement stemmed from a complaint, filed with the New Jersey attorney general’s office by a gay match seeker in 2005, that eHarmony had violated his rights under the state’s discrimination law by not offering a same-sex dating service. In 2007, the attorney general found probable cause that eHarmony had violated the state’s Law Against Discrimination.

As part of the agreement, the Pasadena, Calif.-based company will develop and market Compatible Partners, a Web dating service for same-sex couples, and will allow the site’s first 10,000 users to register free. EHarmony will also pay $50,000 to the attorney general’s office and $5,000 to the man who first brought the case.

In a statement Wednesday, eHarmony denied violating discrimination law and said its business had been based on years of researching opposite-sex marriages to understand what makes such couples compatible.

EHarmony was launched in 2000 by Neil Clark Warren, an evangelical Christian who practiced for years as a clinical psychologist. Dr. Warren is no longer involved in day-to-day management but is the company’s chairman. A spokesman said Dr. Warren had no comment on the settlement beyond the company’s statement.

A fringe activity a decade ago, online dating has soared in popularity, and many of eHarmony’s competitors allow same-sex matches. Consumers are expected to dole out nearly $1 billion in fees for online dating sites this year, according to Forrester Research, and the market is expected to expand by 10% in each of the next five years.

EHarmony is among the most popular dating Web sites, along with such sites as Yahoo Personals and IAC/InterActiveCorp’s Match.com. EHarmony attracted nearly 2.6 million unique visitors in October, a 28% jump from a year earlier, according to comScore Inc.

Read the full story from the Wall Street Journal.