Developer Milt Peterson stands at the site where he wants MGM Resorts to build a high-end casino at National Harbor in Prince George’s County. (Photo by ASTRID RIECKEN For The Washington Post)

Maryland is likely to launch the bidding process for a Prince George’s County casino on Jan. 31, state officials said Wednesday.

Voters authorized a sixth gambling site in November with passage of Question 7, a ballot measure that also allows table games at Maryland’s existing slots sites.

The measure calls for the state to take competitive bids for a new casino from a swath of Prince George’s that includes both National Harbor and Rosecroft Raceway.

MGM Resorts has said it will bid to put an $800 million casino at National Harbor, the 300-acre mini-city on the banks of the Potomac River.

But Penn National Gaming is also considering a bid for Rosecroft Raceway, even though the company spent more than $40 million trying to persuade voters to defeat Question 7.

Penn spokeswoman Karen Bailey said Wednesday that the company is “still considering” whether to compete for the license.

A state commission that picks Maryland’s gambling sites has set its next meeting for Jan. 31. Donald C. Fry, the panel’s chairman, said Wednesday that he expects to issue a request for proposals at the meeting, which would kick off the bidding process.

Interested bidders would probably have until May to submit proposals, Fry said.

State officials are expected to spend several more months weighing the merits of proposals and conducting background checks on applicants.

Under law, the Prince George’s site would not be able to open before mid-2016.