One week after lawmakers and advocates called for his resignation Insurance Commissioner Thomas R. Sullivan quietly resigned Monday.

The resignation was offered verbally and two weeks notice was given according to Gov. M. Jodi Rell’s Chief of Staff M. Lisa Moody, but few details were available late Monday evening. On Tuesday the state released Sullivan’s resignation letter.

In the letter Sullivan promises not to reveal any confidential information he received as Insurance Commissioner upon his return to the private sector.

“I will never use or disclose any confidential information I acquired in the course of or by reason of my official duties as Insurance Commissioner for the financial gain of myself or another person. In addition, for a minimum of one year, I will not solicit, negotiate or accept employment with any company regulated by the Connecticut Insurance Department or any company that received a contract valued at $50,000 or more where I participated in the negotiation or award of the contract,” Sullivan wrote.

Sullivan was unavailable for comment, but consumer advocates like Beverly Brakeman said she was “glad he took our advice.”

Brakeman, public policy director for the United Auto Workers and member of the Insurance Department’s Consumer Council, said she thinks Sullivan “had a lot of heat on him” after he approved a 47 percent increase for nearly 6,000 individuals on Anthem’s Tonik plan.

Sullivan said he approved the rate increase because the federal health care bill required benefits that were much greater than previously offered.

“Removing me as Insurance Commissioner does nothing to address the inconvenient truth that the federal healthcare reform law has caused premiums to increase due to the federal government’s failure to address the rising costs of medical care while simultaneously increasing the value of benefits carriers are required to provide,” Sullivan said last Monday in response to consumers’ outcry.

Advocates and lawmakers said Sullivan should have held a hearing on the proposed rate increase before it was approved.

Commissioner since April 2007 Sullivan came to the Insurance Department with 20 years of experience in the insurance industry.