The Federal Trade Commission will seek to block fantasy sports sites DraftKings and FanDuel from merging, the agency said Monday.
"The proposed merger would create a single provider with by far the largest share of the market for paid daily fantasy sports contests in the United States," the agency stated Monday.
The Boston-based DraftKings is the largest daily fantasy sports company, while FanDuel, founded in Scotland, is the second-largest, according to the FTC.
The agency says it will seek ask a federal judge in the District of Columbia to issue an injunction prohibiting the merger. The FTC also is filing an administrative complaint. The court papers weren't available as of Monday afternoon.
Last year, both DraftKings and FanDuel agreed to pay $6 million each to settle deceptive advertising allegations in New York.
State Attorney General Eric Schneiderman previously sued both companies for allegedly violating state laws against sports betting and unfair advertising. The charges related to unfair advertising centered on allegations that the companies duped consumers about their prospect of winning.
Both companies also briefly stopped operating in New York in 2016, after Schneiderman sued them. But they resumed operations after state lawmakers passed a bill authorizing daily fantasy sports companies to operate in the state. That measure requires such companies to register with the state, and pay taxes equal to 15% of gross revenue generated in New York.