LOS ANGELES — After looking for love on the Internet and failing to find it, frustrated lonely hearts are heading to court, accusing online dating sites of engaging in deceptive practices.

A recent lawsuit against Match.com charged the matchmaking service with sending a female employee out on a date with a male subscriber as ”date bait” to keep him signed up. Another lawsuit against a personals service offered by Yahoo! Inc. accused the Internet portal giant of creating fake profiles to entice subscribers.

Match.com denied the allegations and obtained an affidavit from the woman, who declared she never worked for the company. Yahoo! refused to comment.

The federal fraud lawsuits, which seek class-action status, have roiled the lucrative online dating industry. A 2004 report by Jupiter Research estimated the U.S. Internet personals market had revenues of $473 million that year — the largest moneymaker for online content.

In the Match.com lawsuit, filed Nov. 10 in U.S. District Court in Los Angeles, plaintiff Matthew Evans made the ”date bait” allegation against Autumn Marzec. He also accused the site of using fake profiles and sham e-mail ”winks” from potential matches to keep him subscribed. Match.com offers a basic subscription for $29.99 a month.

Marzec said in a signed affidavit she has never been employed by Match.com or its parent company, InterActive Corp., and has not worked for them as a contractor.