TRELLEBORG, Sweden (March 30)—Trelleborg A.B. is expanding its marine fender business by about $23 million annually with the planned acquisitions of the Fentek Group in Singapore, Australia and Germany. Trelleborg hopes to close deals for Hercules Rubber & Chemicals of Singapore, Queensland Rubber of Australia, and for a majority stake in Fentek Marine Systems in Germany by April 30, the company said. The three firms principally produce marine fender systems, which are sold under the Fentek name, according to Trelleborg. The companies also make civil engineering parts such as bridge bearing systems and tunnel seals.