The Connecticut Insurance Department has approved CVS Health Corp.'s pending $69 billion deal to acquire Aetna Inc.

The approval comes after the insurance department disclosed that CVS pledged to keep Aetna's headquarters in Connecticut for at least 10 more years.

The transaction is expected to close by year-end 2018. The U.S. Department of Justice recently indicated that it would approve the transaction once both companies divest their Medicare Part D plans. In September, WellCare Health Plans Inc. agreed to acquire Aetna's Part D plans.