biggest trading scandals on record, is suing J.P. Morgan & Co. for up to $2.2 billion, alleging fraud, negligence, breach of duty, and racketeering.

The lawsuit seeking $735 million in damages was filed under seal Tuesday in Manhattan's U.S. District Court. If Sumitomo prevails on the racketeering charge the damages would be tripled.

It is the latest in a string of lawsuits filed by Sumitomo in recent months. The Osaka-based company, which is the fifth-largest trading firm in Japan, has accused four banks of helping its former chief copper trader, Yasuo Hamanaka, make unauthorized trades over a period of 11 years, leading to the losses.

In addition to Morgan, lawsuits have been filed against Credit Lyonnais Rouse Ltd., Chase Manhattan Corp., and UBS AG. Observers said more lawsuits are expected.

In a statement, J.P. Morgan said the suit was ''baseless.''

We thoroughly investigated our conduct in this matter and are confident that we acted appropriately,'' a Morgan spokesman said. ''We intend to contest these allegations vigorously.''

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.