The suit, filed in Superior Court, said AOL subscribers have encountered "busy and unavailable phone lines and/or inaccessible computer equipment" since the company began offering unlimited access for a $19.95 fee at the beginning of the year.

The suit, which seeks class-action status, was brought by Richard Basch, Robert Friedland, Jeffrey Rayden and James Kranz of Los Angeles County and Jason Cartwright of San Diego County, said their attorney, Louis Marlin.

Marlin said yesterday his clients were unhappy with AOL because it has become increasingly difficult to get online.

"They try over and over and over again to try and get in and they get a constant busy signal," he said.

The plaintiffs, claiming negligence and consumer fraud, are seeking at least $20 million in compensatory damages as well as punitive damages and attorney fees.

Marlin said that figure is only a minimum estimate "to give warning to the other side that we are seeking significant monetary damages."

The suit also asks for a court order stopping AOL from selling any more flat-fee, unlimited-access service until there is "sufficient equipment" to handle the increased usage. "Every new subscriber they get makes it more difficult for the existing subscriber to connect to the service," Marlin said.

The company said in a statement, "We expect to prevail in the class-action suits addressing member access to AOL. Although we understand the frustration some members are experiencing at not being able to obtain immediate local access during peak periods, the average AOL member gets more value under unlimited pricing than ever before."

It added that the company plans a $250 million addition in capacity over the next two months.

In December, AOL said users were staying online some 3 million hours a day under the new plan - up from 1.6 million hours a couple months before.

A similar lawsuit against AOL was filed in Chicago on Dec. 18, according to plaintiff's attorney Alan Goldberg.