Regulators in Missouri have raised a red flag on Aetna's $34 billion acquisition of , calling the deal anti-competitive for the state's Medicare market. It's the first hurdle in the state merger approval process the insurers have encountered.

The state's director of the department of insurance, John Huff, issued a preliminary order saying that if deal is approved by federal regulators the two firms will have to "cease and desist from doing business throughout the State of Missouri with respect to… Medicare Advantage Markets."