Bacnotan Consolidated Industries, Inc. plans to venture into the geothermal power business as the firm diversifies its interests after selling its cement holdings.  Ramon del Rosario, Jr., president, said Bacnotan plans to form a consortium with foreign firms along with Phinma unit, Trans-Asia Oil and Energy Development Corp., as the lead company, to develop any of these geothermal projects: Palinpinon, Makban, and Tiwi. "We are interested in geother-mal projects. We may participate in the bids by the middle of the year," he added.