Virginia Insurance Commissioner James M. Thomson represented Alexandria in the General Assembly. An article yesterday incorrectly said he represented another jurisdiction.

Virginia Democratic Gov. Charles S. Robb, in the latest of his string of tradition-breaking appointments, today named the first woman to serve on the state's 83-year-old regulatory commission.

Robb, who in 1983 appointed the first black member of the state Supreme Court, named Deputy Attorney General Elizabeth Bermingham Lacy, 40, of Richmond, to a seat on the three-member State Corporation Commission.

The SCC, considered one of the most powerful state regulatory agencies in the country, oversees billions of dollars in utility rate decisions as well as Virginia's insurance, banking and transportation industry and 100,000 businesses incorporated here.

Robb made the appointment only hours after the Virginia Supreme Court rejected a case that stemmed from the failure of the General Assembly, which normally makes SCC appointments, to agree on a candidate during its session that ended last Feb. 23.

Former Fairfax legislator James M. Thomson had sought to force Robb to name him to the post after House and Senate Democrats, who control the legislature, split over his appointment. It was similar to the legislative deadlock in 1983 that allowed Robb to appoint Richmond lawyer John Charles Thomas to the state Supreme Court.

At a hastily called press conference -- Robb said he had made the decision only minutes earlier -- the governor introduced Lacy and acknowledged that he had sought from the begining to name a woman to the seat vacated by Junie L. Bradshaw, who resigned Feb. 1 to enter business.

"I cannot tell you that I did not focus on putting a highly qualified woman on the SCC," Robb told reporters, saying the search for a candidate began immediately after the legislature adjourned.

Lacy, who had only 15 minutes to get to the capitol before the governor's announcement, is deputy attorney general for judicial affairs, a division that prosecutes consumer protection violations, oversees the state's antitrust laws, state regulations and conflict of interest statutes.

"Her qualifications are obvious," said Robb.

Robb characterized the appointment as an effort to show that "public confidence . . . would best be served" by a diversity of qualified appointees to high public office.

Robb said the decision came too late today to notify Democratic leaders of the General Assembly, who had squabbled over the sought-after political patronage jobs.

Under Virginia law, Lacy's appointment officially will continue only until 30 days into the next General Assembly, which convenes in January, although Robb said today that he expects the appointment will be confirmed by the legislature for a full six-year term.

Lacy will serve in the $64,000-a-year post as a commissioner, but also will hold the title of judge, since the SCC has judicial authority over regulatory decisions that can only be appealed to the state Supreme Court.

Before working state Attorney General Gerald L. Baliles' office, Lacy worked for the Texas attorney general and drafted that state's consumer protection act.