credit ratings on Bermuda-based Mutual Risk Management Ltd. to single-A-minus The international insurance power was previously rated triple-B-plus.

Major factors in the improved standing were MRM's "very strong operating performance'', its conservative operating leverage ratio of four-to-one limiting gross premium written to capital, and its "seasoned management''.

"The management team is strong and stable, with an average of more than 15 years in the business and more than 10 years at MRM companies,'' according to a statement issued by S&P to explain the upgrade.

"MRM continues to demonstrate strong growth in earnings from operations, with consolidated 1998 net earnings up 33 percent to $63.5 million and return on revenue of 26 percent.

"Return on revenue has averaged 28 percent over the past three years, with return on equity averaging 21 percent.'' But S&P also found MRM was "more dependent on third parties than most insurers in its peer group'' since MRM's fee-based business was based on the continued availability of strong retrocessional cover.

And MRM continued to rely on workers' compensation for the bulk of its revenues although the growth in programme business had seen this line reduced to less than 50 percent of 1998 net written premium.

Looking to the future S&P said acquisitions would continue to be part of the MRM growth strategy but the "magnitude of the acquired operations is expected to remain modest''.

S&P also heightened MRM's subordinated debt rating to triple-B-plus from triple-B.

The senior debt to capital ratio is less than one percent and is not expected to exceed twenty percent prospectively, with cash debt service coverage at or above ten times.