Shares of U.K.-listed Nigerian oil producer Lekoil slumped 69% as the company said it appeared to have been defrauded by individuals who pretended to be representatives of the Qatar Investment Authority. Lekoil on Jan. 2 had announced a $184 million loan from the QIA to fund drilling and development of a field. The QIA on Jan. 12 told Lekoil's advisers that it was not the counterparty. Lekoil said its exposure is $600,000 for the initial arrangement and legal fees. Including that exposure, Lekoil said it had $2.7 million in cash as of Dec. 31.