March 7 (Reuters) - U.S. oil producer Hess said

on Thursday it was reviewing the timeline for closing its merger

with Chevron ( CVX ), after oil major Exxon Mobil ( XOM )

signaled a potential counter offer for Hess's Guyana assets.

Exxon on Wednesday filed a contract arbitration claim

related to Hess' proposed sale of its Guyana oil properties and

suggested it may counter Chevron's ( CVX ) pending deal for the assets.

The arbitration case seeks to preserve Exxon's right to

evaluate making a bid for Hess' 30% stake in the giant Stabroek

offshore oil block if Chevron ( CVX ) proceeds with its proposed $53

billion purchase of Hess.

Hess said on Thursday it disagreed with Exxon's

interpretation of the agreement and were confident that its

position will prevail in arbitration.

Chevron's ( CVX ) acquisition of Hess has been stalled by the U.S.

Federal Trade Commission's request for additional information on

the merger. That request pushed back any closing to at least the

middle of this year.