The "University of California System" had 206 operational companies in 2004. It formed five new ones that year.
In the same year, the research income was $2792 million. The system filed 965 patents.
These numbers come from Nature Biotechnology (vol 24, p 13) where Stacy Lawrence reviews tech transfer at US universities. "New company formation (about half of which is biotech) from US research institutions was way up in 2004 (up to >460)."