NEW YORK (Reuters) - JPMorgan Chase & Co. , one of many investment banks sued for rigging initial public offerings during the bull market of the 1990's, agreed in principle to pay $425 million to settle its portion of the case.

JPMorgan (Research) spokesman Joseph Evangelisti said Thursday evening an agreement had been reached in principle and that the settlement "would have no adverse effect on our financial results."

The agreement is subject to approval by investors represented by the class action lawsuit and by two judges presiding over the case in Manhattan federal court.

Dozens of Wall Street underwriters were sued after technology stocks went public and soared during the bull market, only to implode starting in 2000.

Investors who lost all or most of their investments filed hundreds of lawsuits against the companies and their underwriters, seeking billions in damages.

One class action lawsuit claimed banks manipulated the market in hundreds of technology IPO's. A second lawsuit accused 12 banks of colluding to rig IPO's, violating antitrust law.

By being first to settle, JPMorgan, the nation's No. 3 bank, may put pressure to settle on rivals such as Morgan Stanley (Research) and Goldman Sachs Group Inc. (Research)

Melvyn Weiss, who represented the plaintiffs, said he hopes the other banks will follow JPMorgan's lead and settle.

"I think it's very significant when a major defendant in a multiple-defendant case settles," Weiss said. "Frequently, there's a spiraling effect because you don't want to be the last one standing. I would hope that they see this as a signal to wrap this up."

JPMorgan was among the last to settle the main investor lawsuit over the collapse of Enron Corp. It agreed last June to pay $2.2 billion, which relative to the amount of work it did for the energy merchant was more than other banks paid.

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