At the Los Angeles-based firm's annual meeting, shareholders approved a boost to 130 million from 65 million in the authorized common shares. Chairman and Chief Executive Paul A. Miller said the extra shares will likely be used to make one or more acquisitions in the services industry. The company, parent of Southern California Gas Co., has indicated that it wants to diversify into the services field by 1987. A spokesman said no specific acquisition candidates have been identified. Shareholders also approved a change permitting the board to have between nine and 19 members, compared to 12 to 14 previously.