Irvine Co. Executive to Retire in June

Richard G. Sim, the Irvine Co. executive who oversaw development of the vast Spectrum business park in south Orange County, said Thursday that he will retire June 30.

Sim, who turns 65 in August and was expected to retire soon, is chairman of the investment property group at Irvine Co., the private Newport Beach company that is subdividing the 140-square-mile Irvine Ranch.

Clarence Barker, the group’s president, has been groomed to replace Sim and, among other things, lead a further expansion of the Spectrum. The business park is one of the largest and most successful business parks in the nation.