Standard & Poor's Corp. has raised its claims-paying ability ratings of Terra Nova Insurance Co. Ltd. and Terra Nova (Bermuda) Insurance Co. Ltd. to A from A- and the senior debt rating of Terra Nova Insurance (UK) Holdings P.L.C. to BBB from BBB-. The rating changes reflect the continued enhancement of Terra Nova Group's overall profile, including a stronger-than-expected operating performance in 1996 and success in securing a significant participation in the Lloyd's market, according to the rating agency. . . .Pembroke Ltd., a newly formed claims adjusting company, has been awarded a contract to adjust London market excess-of-loss claims for Equitas Holdings Ltd. It is the first contract for Pembroke, which was launched at the beginning of this month by Alan Piper, the former claims manager for Lloyd's non-marine syndicate 219. . . .CIGNA Re Europe has opened an office in Monte Carlo, Monaco. The branch office will be operated by Executive Director Rolf Zeijdel, formerly in CIGNA Re Europe's Brussels, Belgium, office. . . .The World Insurance Network, an electronic exchange system for insurance transactions created by a group of the world's largest brokers, has named Richard Wales chief executive officer. Mr. Wales previously was group director of information technology for Sedgwick Group P.L.C., which is one of the WIN partners. He also held the title of chief operating officer at WIN, which he will retain, while maintaining his position with Sedgwick. With WINconnect's desktop interface service due to become operational July 1, "the next eight months will be crucial not just in the roll-out of WIN but also in shaping the future of the commercial insurance industry," he said. . . .Willis Corroon Group P.L.C. reported a 5% decline in pretax profits for the first quarter of 1997 to 45.7 million pounds ($73.7 million), compared with the year-earlier period. Executive Chairman John Reeve blamed the broker's lower profits primarily on the fall in insurance rates resulting from intensifying competition among underwriters. . . .London-based reinsurance company Benfield Group Ltd., whose founder, Matthew Harding, died in a helicopter crash last October, made a pretax profit for the 18 months to Dec. 31, 1996, of 46 million pounds ($78.8 million), against a 32.9 million pounds ($51.1 million) profit for the 12 months to June 30, 1995. The latest figures included 16 million pounds ($27.4 million) from a key-employee life insurance policy on Mr. Harding. Operating profit for the Benfield Group, which has moved its fiscal year end to Dec. 31 to better reflect the reinsurance cycle, improved by about one-third to 37.1 million pounds ($63.5 million), of which 33.9 million pounds ($58.1 million) came from brokering and 3.2 million pounds ($5.5 million) came from underwriting.