Leisure Technology in Joint Venture: Japanese steelmaker Nisshin Steel Co. has formed a $71-million joint venture with Leisure Technology to build retirement homes in the United States, Canada and Mexico. The initial deal could grow in value to $1 billion if the companies build all 44 projects they plan. Nisshin is to put up $37 million over the next five years. Leisure Technology, which has retirement developments under the name Leisure Village, will provide $10 million cash and $24 million worth of land through its LeisureCare division. The first project on the drawing boards is a 250-unit retirement home in the Chicago suburb of Wheeling, Ill.