By Peter Henderson

SAN FRANCISCO, June 5 (Reuters) - Two of California's biggest cities on Tuesday appeared on the verge of adopting sweeping pension reform, according to early election results, which showed measures in both cities passing by 2-1 margins.

Voters in San Diego, second in population to Los Angeles, favored moving new employees to plans similar to private-sector 401(k)s, instead of pensions with guaranteed benefits.

The city of San Jose, California's third largest, will force employees to choose between sharply lower benefits or sharply higher employee contributions to maintain current benefits.

Both sets of results were based on about 16 percent of precincts. (Reporting by Peter Henderson; Editing by Lisa Shumaker)