Connecticut Attorney General Richard Blumenthal said he will ask the state’s insurance regulators to block MetLife Incorporated’s $11.5 billion purchase of Travelers Life & Annuity because of job losses.

The planned purchase from Citigroup goes against the public’s interest because MetLife plans to cut hundreds of Travelers jobs in Hartford, Conn., Mr. Blumenthal said in a statement yesterday.

A MetLife spokesman, John Calagna, said the company expected to complete the acquisition in July and declined to comment on Mr. Blumenthal’s opposition.

“My message to MetLife is simple: Keep jobs in Hartford or keep your hands off Travelers,” Mr. Blumenthal said in the statement.

The attorney general has no authority to block the purchase himself, and is urging the Connecticut Insurance Department to withhold approval.

New York-based MetLife is the biggest American seller of life insurance sold through employers and would become the largest life insurer for individuals with the Travelers purchase.

MetLife plans to cut about 600 jobs in Hartford, and move another 100 positions out of state, Mr. Calagna said. That would reduce Travelers’ Connecticut workforce of 1,800 by about 39%, he said. Mr. Blumenthal put the projected job losses at 800, without saying where he obtained the information.

Connecticut’s insurance regulators sent MetLife an 11-page letter Tuesday requesting more information about the purchase. Most questions were unrelated to job cuts, according to a copy of the document. “The application is not yet deemed complete,” said a spokeswoman for the insurance department, Kate Kiernan-Pagani. Ms. Kiernan-Pagani said she was unaware of any instance in which the department denied an acquisition or merger request because of job losses.