The Industrial Bank of Japan and Dai-ichi Mutual Life Insurance Co. announced Friday a plan for a broad-based business tieup designed to strengthen each side to survive the Japanese "Big Bang" financial deregulation.The move is the latest business alliance to be announced among the major Japanese financial institutions as they gear up to slug it out in a highly anticipated and newly designed financial arena. Though the two firms plan to boost their capital stakes in each another and work together on asset management, product development and lending services, it could just be an indicator of a much larger scheme.In May, IBJ announced it would form a joint venture with Nomura Securities Co. to develop financial derivatives. If IBJ's agreement with Dai-Ichi Mutual becomes reality, the three would be poised to construct a much more impressive alliance that would be able to provide services and products in banking and securities as well as insurance.At a news conference, IBJ President Masao Nishimura and Dai-ichi Mutual Life President Tomijiro Morita said that, through March 2000, Dai-ichi Mutual would up its stake in IBJ while IBJ pumps money into a Dai-ichi Mutual fund functioning as capital for stock firms. Dai-ichi Mutual holds a 2.5-percent stake in IBJ.The cross-ownership would be kept under 10 percent, as stipulated by the Antimonopoly Law, Morita said.