In October, the Justice Department approved the merger of CVS, a pharmacy chain and benefits manager, and Aetna on condition that the health insurer sell its Medicare Part D drug plan business to WellCare Health Plans Inc. Most deals struck between the government and companies to resolve antitrust concerns are approved by federal courts with little fuss under the 1974 Tunney Act, which requires courts to ensure the agreement is in the public interest. Companies generally do not wait for final court approval before closing their transactions.