SAN JOSE, Calif., July 13 -- Cisco Systems Inc. said it would pay $150 million in stock to buy AuroraNetics Inc. Cisco said the acquisition of the privately held developer of silicon technology for metropolitan fiber networks is expected to close in the first quarter of its fiscal year ending in October 2002. It was Cisco's first announced acquisition this year. Last year the company purchased 23 firms in deals ranging in value from $20 million to almost $6 billion. The previous year it closed 18 deals, with values ranging from $25 million to $7 billion.