Marsh & McLennan Cos. Inc. is buying Brockman & Schuh Group in Mexico City for an undisclosed sum. Brockman & Schuh was a member of the Johnson & Higgins-led UNISON network. It has revenues of nearly $50 million and 15 offices in Mexico as well as Colombia, Guatemala and Miami

. . . .Munich Reinsurance Co. has opened representative offices in Beijing and Shanghai, China. Having conducted reinsurance business in China for 25 years from its Hong Kong office, Munich Re said that it now anticipates "further dynamic growth and a continuing process of liberalization in the Chinese insurance industry."*.*.*.Lloyd's of London has carried out a recommendation made in May by its Regulatory Review Group to set up a Market Risk Unit to monitor and control the aggregate risks faced by syndicates in the Lloyd's market. The Market Risk Unit, led by Roger Sellek, former head of Lloyd's commercial policy unit, will identify areas of systemic risk within the market, assess aggregate exposures and develop approaches to evaluate and limit these risks and exposures. . . .Swire Blanch International (Holdings) Ltd., a joint venture of Minneapolis-based E.W. Blanch Holdings Inc. and Hong Kong-based Swire Group, is acquiring Buenos Aires, Argentina-based Walbaum Americana S.A. and its related businesses in Paraguay and Uruguay. Walbaum Americana provides insurance and reinsurance intermediary services. Swire Blanch said the deal, expected to be completed by mid-November, "provides a significant international expansion vehicle" for it into the Latin American mar-kets. . . .Creditors of Orion Insurance Co. P.L.C. and London & Overseas Insurance Co. P.L.C. will receive an initial payment of 15% of what they are owed, according to Paul Evans, the scheme administrator from Price Waterhouse. At the end of 1996, the two insurers' liabilities exceed assets by $772 mil-lion. . . .Angerstein Underwriting Trust P.L.C., one of the leading corporate capital vehicles in the Lloyd's market, is concentrating its 1998 underwriting capacity on fewer syndicates. Its total capacity for 1998 will be about 200 million pounds ($320 million) on 54 syndicates, compared with 197 million pounds ($336.9 million) on 67 syndicates for 1997. "It is vitally important to be on the right syndicates in a down cycle," said Angerstein Chief Executive John Stace. . . . Sedgwick Reinsurance Brokers has become the first on-line subscriber outside the United States to the Catastrophe Risk Exchange system. CATEX is the largest inter-connected electronic insurance market, with clients representing 10% of global property and casualty premiums.