Price/Stern/Sloan Publishers Inc. has completed an agreement to purchase the assets of HP Books Inc., a wholly owned subsidiary of Knight-Ridder Inc., for $14 million in cash . . . Oakland-based World Airways reached a tentative agreement on a five-year contract with the Teamsters Union, subject to ratification by World's cockpit crew members . . . Genentech Inc., South San Francisco, and Japan's largest chemical company, Mitsubishi Chemical Industries Ltd., signed a five-year agreement to exchange certain marketing rights and collaborate on research . . . Circuit City Stores said shareholders approved an increase to 2 million from 250,000 the number of authorized preferred shares . . . In Scottsdale, Ariz., Fidelity National Financial Inc. announced that it has signed a definitive agreement to acquire 100% of the stock of San Francisco-based Western Title Insurance Co. for $31 million.