NEW YORK (Bloomberg) ? American International Group Inc. won a restraining order after accusing an insurance agency controlled by ousted Chairman Maurice (Hank) Greenberg of entering into an unauthorised contract with Berkshire Hathaway Inc.

The order bars Starr Technical Risks Agency, a unit of Greenberg?s C.V. Starr & Co., from reinsuring AIG policies with Berkshire?s National Indemnity unit, New York State Supreme Court Justice Herman Cahn said yesterday. It stands until AIG and C.V. Starr resolve the matter in arbitration.

AIG, the world?s largest insurer, sought restrictions on C.V. Starr in a January 27 legal motion, saying the firm was trying to hijack its business.

The claims underscore the increasing acrimony between AIG and Greenberg, whom the company removed last year amid an accounting probe.

?The lack of an injunction would permit Starr Tech to continue to erode AIG?s reputation with its reinsurers,? Cahn?s order said.

C.V. Starr is considering an appeal, attorney David Boies told Cahn at a hearing in Manhattan.

?We?re delighted with the judge?s opinion,? said AIG attorney Michael Carlinsky.