The UC Board of Regents has approved a proposal to cap out-of-state undergraduate enrollment at 18 percent.

State lawmakers last year withheld $18.5 million unless the system adopted a cap.

Four popular campuses that currently exceed the 18 percent cap will be allowed a higher cap pegged to next year's enrollment. Those campuses include UC Berkeley at 24 percent; UC San Diego and UCLA at 23 percent; and UC Irvine at 19 percent.

The public university system benefits from higher out-of-state tuition but hears complaints from California undergraduates who say they are being squeezed from coveted spots by wealthier nonresidents.