Marathon Asset Management LP, the hedge fund that called on American Airlines to broaden talks with creditors in its bankruptcy case, wants a court-ordered investigation into an inter-company debt deal at the airline, Bloomberg News reported yesterday. AMR Corp.'s American took on $2.26 billion in debt before last year's bankruptcy filing that regional carrier American Eagle owed under aircraft-financing agreements, Marathon said in a court filing yesterday. "The pre-petition transactions raise serious questions as to whether American Airlines received fair value in exchange for incurring the billions of dollars in debt and as to whether these transactions were otherwise improper," Marathon said.