LOUISVILLE, Ky. (WDRB) --  Louisville-based Humana Inc. and its suitor Aetna Inc. have mutually extended the “end date” of their merger agreement from June 30 to Dec. 31, according to filings Friday afternoon with the U.S. Securities and Exchange Commission.

The “end date” is a point at which either company can call off the deal if it is not already consummated.

When Aetna agreed to buy Humana for $37 billion last July, the merger agreement gave either company the option to extend the end date to Dec. 31.

The companies have said the deal is on track to close by the end of the year, but it still needs approval from federal authorities.

On Thursday, California’s insurance commissioner urged national antitrust regulators to block the deal, saying it would be anti-competitive. 

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