California regulators have given the green light to a $6.6 billion merger that would join two major power companies in Southern California, creating the largest utility company in the nation.

The deal approved Tuesday would join San Diego-based Enova Corp. with Pacific Enterprises of Los Angeles to form a new company to compete in California's deregulated electricity market.The merger still requires final approval from the Federal Energy Regulatory Commission, the U.S. Justice Department and the federal Securities and Exchange Commission.