NEW YORK - Share­hold­ers of JP­Mor­gan Chase & Co. have filed two law­suits against the biggest US bank, ac­cus­ing it and its lead­ers of tak­ing ex­ces­sive risk and caus­ing a mon­u­men­tal US$2 bil­lion trad­ing loss. The com­pa­ny dis­closed the loss last week, say­ing it re­sult­ed from a failed hedg­ing strat­e­gy.

The law­suits filed yes­ter­day in New York claim JP­Mor­gan changed its risk mod­el with­out telling in­vestors. They say the shift led to the loss­es and claim com­pa­ny lead­ers mis­led in­vestors. One suit was filed by Cal­i­for­nia share­hold­er James Bak­er. A sec­ond was filed by share­hold­er Ari­zona-based Sarato­ga Ad­van­tage Trust's fi­nan­cial ser­vices port­fo­lio.

JP­Mor­gan de­clined to com­ment. Mean­while, FBI Di­rec­tor Robert Mueller said Wednes­day the bu­reau has launched a pre­lim­i­nary in­ves­ti­ga­tion of JP­Mor­gan fol­low­ing the US$2 bil­lion trad­ing loss at the bank. Mueller's com­ment at a Sen­ate Ju­di­cia­ry Com­mit­tee hear­ing was the first on-the-record con­fir­ma­tion of the pro­bel.

On Tues­day, a law en­force­ment of­fi­cial said that the FBI's New York of­fice is head­ing an in­quiry in­to the JP­Mor­gan loss. Un­der at­tor­ney gen­er­al guide­lines for FBI op­er­a­tions, a pre­lim­i­nary in­ves­ti­ga­tion may be ini­ti­at­ed on the ba­sis of any al­le­ga­tion or in­for­ma­tion in­dica­tive of pos­si­ble crim­i­nal ac­tiv­i­ty.

Time lim­its are set for com­ple­tion of pre­lim­i­nary in­ves­ti­ga­tions - usu­al­ly six months, al­though six-month ex­ten­sions can be grant­ed. Ex­ten­sions of pre­lim­i­nary in­ves­ti­ga­tions be­yond a year must be ap­proved by FBI head­quar­ters.

AP