(Reuters) - The U.S. Federal Trade Commission is expected to greenlight U.S. oil producer Chevron's purchase of Hess as soon as this week, two people familiar with the matter said, leaving Exxon Mobil's challenge to the $53 billion deal as its final hurdle.

The U.S. Federal Trade Commission is expected to approve Chevron's (CVX) $53B acquisition offer for Hess (NYSE:HES) as soon as this week, Reuters reported Monday, which would leave Exxon Mobil's (XOM) challenge to the deal as the only remaining obstacle.

The proposed merger was first announced last October, and the FTC sent a second information request to Chevron two months later