Aug. 15 (Bloomberg) -- Basis Capital Fund Management Ltd., an Australian hedge fund battered by declines in the U.S. subprime market, said losses in its Yield Fund may exceed 80 percent. The hedge fund has been unable to ``accurately estimate'' the net asset value of units in the fund because of ``further deterioration of market conditions,'' Basis said today in a letter sent to investors and obtained by Bloomberg News. Basis Capital last month hired Blackstone Group LP as an adviser to negotiate with creditors.