(Adds share move, claim details)
May 28 (Reuters) - London-listed shares in oil and gascompany Ithaca Energy fell by as much as 18percent after the Calgary-based firm said it had received alegal claim regarding its Greater Stella Area oil field in theNorth Sea.
The company, which denied any wrongdoing, said a statementof claim had been lodged complaining it had misrepresented theschedule for completing modifications at a floating productionfacility.
Ithaca said in February that modifications to the "FPF-1"facility, being carried out by UK oil services firm Petrofac Ltd, would not be completed until 2016.
Ithaca noted that the statement of claim had come from a lawfirm that advertises itself as undertaking investor law suits.
Toronto-based law firm Morganti Legal said in March that itwas investigating whether Ithaca's views about the completiondate of FPF-1 were "overly optimistic".
Morganti and Petrofac were not immediately available forcomment.
Ithaca's London-listed shares fell as low as 42.5 pencebefore recovering to 49.49 pence, down 5.3 percent by 0820 GMT. (Reporting By Mamidipudi Soumithri in Bengaluru; Editing byAnupama Dwivedi and Rodney Joyce)