March 27 (Bloomberg) — Orange County, California's $11.5 billion pension is putting together a fund open to smaller retirement plans to give them access to private-equity investments at a lower cost.

The county selected London-based Pantheon Ventures LLP yesterday to manage the pool. For the past 10 months, Orange County's Employees Retirement System has been collaborating with other California pensions to develop the fund, which would give them leverage when negotiating fees with private-equity firms.

Orange County, south of Los Angeles, plans to invest $50 million to $100 million annually over three years. It may save as much as $5 million a year in fees, more than the system pays investment staff, according to a memo. Pensions from California's San Bernardino County to the state of Wyoming are considering joining the fund, according to officials at both plans.