Corroon & Black Corp. on Tuesday rejected an unsolicited $840 million takeover bid from Aon Corp., saying it would proceed with its proposed merger with fellow insurer Willis Faber PLC of Britain. Corroon & Black said the planned stock-swap merger ``will serve the best interests of our shareholders, customers and employees.'' Aon, the holding company for the brokerage Rollins Burdick Hunter Group Inc., offered last week to buy Corroon & Black for $40 a share in cash, or about $840 million. Under the approved agreement, Corroon & Black stockholders would receive 7.8 Willis Faber shares for each Corroon & Black share, or $33.49 at current market prices, in a deal valued at $754 million. Corroon & Black shareholders are scheduled to vote on the merger with Willis Faber on Sept. 28. Aon officials could not be reached for comment Tuesday evening shortly after Corroon & Black issued its response. Corroon & Black stock closed at $35.50, down 37{ cents a share, in New York Stock Exchange composite trading Tuesday before the company's announcement. Aon said last week it would not pursue a bid opposed by the Corroon & Black board. Noting that statement, Corroon & Black said it ``has replied to Aon Corp. that it wishes to consider the matter closed and proceed with the merger with Willis Faber.'' Insurance industry analysts expected Corroon & Black to reject Aon's offer, but they said Aon might come back with a higher bid. Corroon & Black and Willis Faber are the world's fifth- and sixth-largest insurance brokerages, respectively. Their tentative merger, announced in early June, would allow both firms to expand in the other's home market and eventually move into continental Europe and the Pacific Rim. The new firm, Britain-based Willis Corroon PLC, was expected to have 1990 revenue of about $1 billion. It would create the world's fourth-largest insurance brokerage in terms of revenue. Corroon & Black has nearly all its business in the United States, while Willis Faber gets about 80 percent of its revenue from Britain. Corroon & Black sold its 29.9 percent interest in the British broker Minet Holdings PLC in February 1988. Aon has operations in the United States, Canada, Europe and the Pacific. Besides Rollins Burdick, its subsidiaries include Combined Insurance Co. of America and Union Fidelity Life Insurance Co.
