A worker makes his way through the gaming floor at Maryland Live! in Anne Arundel County, one of six casinos currently authorized in Maryland.

Bidding for a Prince George’s County casino officially began on Wednesday.

The state of Maryland issued a “request for proposals,” inviting companies interested in operating a Las Vegas-style venue to make their intentions known by May 10.

MGM Resorts, one of the nation’s largest gambling companies, has said it plans to submit a proposal for a high-end casino at National Harbor, the 300-acre mini-city on the Potomac River.

Meanwhile, Penn National Gaming, another national player in the industry, has said it is considering offering a bid to build a facility at Rosecroft Raceway, the horse-track in Fort Washington.

A state panel is aiming to pick a winning bidder by the end of the year. The same panel signed off on issuing the request for proposals at a meeting last week.

Under state law, the earliest a Prince George’s casino would be likely to open is mid-2016.

The proposal issued Wednesday calls for a casino with up to 3,000 slot machines and allows table games such as black jack and roulette.

Operators are allowed to keep up to 38 percent of slots proceeds and 80 percent of table game revenue.