Oakland-based Kaiser Aluminum & Chemical and the United Steelworkers of America announced a tentative contract agreement believed to incorporate concessions by the union . . . Santa Clara, Calif.-based Intel Corp. reported that it has filed a countersuit against NEC Corp. for copyright infringement of Intel's 8086 microcode by NEC's V series . . . City Investing Co., New York, said it has completed its previously announced sale of Motel 6 Inc. for $565 million in cash to an investor group led by Kohlberg Kravis Roberts & Co.