NEW YORK (Reuters) - Stocks closed lower in a choppy session on Wednesday, with the S&P 500 logging its fourth straight decline as investors worried about Greece's future as a member of the euro zone. Early U.S. gains were erased after the European Central Bank said it had stopped providing liquidity to some Greek banks that had not been recapitalized. The ECB's move caused some market confusion, adding to volatility as traders have a quick trigger finger when it comes to news about Greece. ...

NEW YORK (Reuters) - JPMorgan Chase & Co was the target of two separate lawsuits by shareholders on Wednesday, accusing the bank and its management of excessive risk that led to trading losses of at least $2 billion. A spokesman for JPMorgan Chase declined to comment on the lawsuits, which were filed in U.S. District Court in Manhattan, days after Chief Executive Jamie Dimon's May 10 statement that a "failed hedging strategy" caused the massive loss over the last month. ...

(Reuters) - J.C. Penney Co Inc shares plunged nearly 20 percent on Wednesday, their worst decline ever, wiping away $1.43 billion in market value a day after the retailer shocked Wall Street with a much worse-than-expected drop in sales and by scrapping its dividend. A number of leading Wall Street firms also lowered their price targets on the company. Penney shares closed down $6.57 at $26.75 on the New York Stock Exchange. ...

DETROIT (Reuters) - Major automakers will launch new models through 2016 in the United States at a faster pace than in the last two decades, according to a Bank of America Merrill Lynch report. New models draw more traffic to showrooms, which can boost a company's market share, profit and stock price. Automakers are expanding their lineups to better compete in the growing U.S. auto market after a "lull" during the economic downturn, the annual report said. ...