Shareholders of New World Pictures adopted an amendment to the company's certificate of incorporation regarding the limitation of certain liabilities of company directors and approval of the company's 1986 incentive and other stock option plan . . . The University of Southern California and AT&T signed a $21.8-million contract under which AT&T will design, develop, install and maintain a new network linking 11,000 users in 185 buildings in University Park and on the Health Sciences campuses by March, 1988 . . . Home Shopping Network said it has won FCC approval to purchase three UHF television stations, in Newark, N.J.; Smithtown, N.Y., and Marlborough, Mass. . . . Tylan Corp. of Carson said it expects to report a $9.4-million loss for its fiscal year ended June 30, compared to a $2.2-million profit a year earlier . . . National Semiconductor signed an agreement with NMB Semiconductor of Japan for the development of advanced semiconductor components, which are to be manufactured at NMB facilities in Japan and marketed worldwide by National Semiconductor . . . Japanese and U.S. negotiators began talks aimed at revising a 34-year-old civil air transport agreement between the two countries, a U.S. Embassy official in Tokyo said.