OmniSource of Laguna Hills has acquired a 65% stake in Sullins Electronic, a San Marcos electronic components company, in a stock swap valued at $9.1 million. Under the agreement, OmniSource will exchange 2.275 million shares of its common stock for 65% of Sullins' capital stock outstanding. Sullins' 1987 revenues exceeded $7 million. The company employs more than 100 people. OmniSource is a manufacturer of electronic components, nutritional and medical products. The firm employs 185 people, 15 of whom work in Laguna Hills.