Ms. Ruthardt has headed the department since former Republican Gov. William F. Weld appointed her in 1993.

Published reports have suggested she might be replaced as commissioner by her first deputy, Julie M. Bowler, a former aide to Gov. Swift. Ms. Bowler has been with the department since 1998.

During her tenure Ms. Ruthardt has been a frequent target of complaints by consumer activists who say she is too cozy with the industry she regulates. Her background includes a stint as risk manager at Raytheon Co. of Lexington, Mass. and as national executive for Girl Scouts USA.

One of the biggest flaps that emerged during her commisionership developed over her decision to permit Electric Mutual Liability Insurance Co. to move from Massachusetts to Bermuda. Emlico, which insured General Electric Co. for environmental liability, declared itself insolvent a few weeks after domesticating offshore.

Reinsurers, Massachusetts legislators and consumer critics said Emlico lied about its financial state before moving to the island jurisdiction with laws that would make it easier to pass on its debts to reinsurers. Lawsuits that resulted eventually ended with settlements.

During Ms. Ruthardt's tenure there have been auto insurance rate cuts nearly every year.