NEW YORK (Reuters) - Standard & Poor's yesterday cut its counterparty credit ratings on Ram Reinsurance Co. Ltd. by five notches, citing the bond reinsurer's decision not to write new business.

S&P also cut the senior unsecured rating on Bermuda-based holding company Ram Holdings Ltd. to junk status from investment grade.

Ram Re "has adopted a strategy of not writing any new business until market conditions stabilise, effectively putting the company into run-off," S&P credit analyst Dick Smith said in a statement. Operating companies in run-off are typically given financial strength ratings no higher than BBB, he said.

Ram Re's counterparty credit and financial strength ratings were cut to BBB-minus, the lowest investment grade, from A-plus. RAM Holdings' senior unsecured ratings were cut to BB-minus, the third-highest junk rating, from BBB.

The company has also decided to cease being an SEC-registered company, which means it no longer will be required to file financial statements regularly, S&P said.

Most ratings were put on review for another possible downgrade while S&P reviews the company's capital position, Smith said.