* Investors said silver prices driven down illegally
* HSBC previously dropped as a defendant
* Dozens of lawsuits had been consolidated
March 18 (Reuters) - JPMorgan Chase & Co has won thedismissal of a nationwide investors' lawsuit accusing thelargest U.S. bank of conspiring to drive down silver prices.
U.S. District Judge Robert Patterson in Manhattan said theinvestors, who bought and sold COMEX silver futures and optionscontracts, failed to show that JPMorgan manipulated prices attheir expense, including by amassing huge short positions thatwere not justified by market events at the time.
In a decision made public on Monday, Patterson said thatwhile the investors showed that JPMorgan had the ability toinfluence prices, a fact the bank did not dispute, they failedto show that the bank "intended to cause artificial prices toexist" and acted accordingly.
A lawyer for the investors did not immediately respond to arequest for comment.
JPMorgan did not immediately respond to a similar request.
Investors had, in at least 43 complaints filed in 2010 and2011, accused banks of amassing hundreds of millions of dollarsin illegal profit by manipulating silver prices.
After the lawsuits were consolidated, HSBC Holdings Plc was dropped in September 2011 as a defendant, leavingJPMorgan and 20 unnamed individuals as defendants.
Patterson had rejected the investors' claims in December,but gave them one last chance to bolster their case.
The complaint had sought triple damages for what it calledJPMorgan's antitrust violations in distorting silver pricesbetween 2007 and 2010, including through alleged "fake" tradeslate in the day when market volume was thin.
The Commodity Futures Trading Commission began probingallegations of silver price manipulation in 2008, and two yearslater proposed regulations to give it greater power to thwarttraders who try to manipulate prices.
The case is In re: Commodity Exchange Inc Silver Futures andOptions Trading Litigation, U.S. District Court, SouthernDistrict of New York, No. 11-md-02213.