U.S. judge blocks Aetna, Humana merger

A U.S. federal judge has blocked Aetna's $37 billion acquisition of Humana, noting the insurance company megamerger would diminish competition.

In his opinion, Judge John Bates of the U.S. District Court for the District of Columbia wrote that Aetna and Humana compete in the Medicare Advantage market, and the merger would substantially lessen competition.

"In that market, which is the primary focus of this case, the merger is presumptively unlawful -- a conclusion that is strongly supported by direct evidence of head-to-head competition as well," he wrote.

The U.S. Department of Justice (DOJ) filed a lawsuit in July 2016 to block the merger, arguing the acquisition would lead to higher prices for consumers. Last July, the DOJ also sued to block Anthem's $54 billion acquisition of Cigna, claiming the merger would hurt businesses and individuals. An opinion has yet to be made on the Anthem-Cigna lawsuit.