A highly rated Bermudian oil captive is no longer taking part in the assessment activities of the rating agency AM Best.

Jamestown Insurance Company Limited is captive to Hess Corporation, the new subsidiary of Chevron Corporation after the latter prevailed over Exxon Mobil Corp in a legal battle and finalised a $55 billion takeover of Hess in July.

The energy company was involved in a legal dispute over Hess’s offshore oil assets in the South American nation of Guyana, and the outright acquisition of Hess depended on the outcome.

The final ruling by the International Chamber of Commerce this summer was a huge win for Chevron, which had sought to buy Hess to gain access to the vast Guyana oil reserves.

AM Best has affirmed the financial strength rating of A- (Excellent) and the long-term issuer credit rating of “a-” (Excellent) of Jamestown Insurance Company Limited (Jamestown) (Bermuda).

While the outlook of the credit ratings is stable, AM Best concurrently withdrew the ratings as the company had requested to no longer participate in AM Best’s interactive rating process.

The ratings reflect Jamestown’s balance sheet strength, which AM Best assesses as very strong, as well as its adequate operating performance, limited business profile and appropriate enterprise risk management.

As a single-parent captive, the company’s mission is to provide insurance and reinsurance coverage for specific risks including property, control of well, redrill, pollution, and liability on behalf of Hess Corporation and its new ultimate parent, Chevron Corporation.

The captive enhances underwriting flexibility for Chevron Corporation by offering direct access to the reinsurance market and supporting more stable, predictable pricing.

Industry reports noted that while Exxon Mobil lost its arbitration challenge to block Chevron’s $55 billion Hess acquisition deal, the top US oil producer managed to delay the tie-up by more than a year, costing its rival billions in lost Guyana oil revenue and slowing integration.