Parx Casino became the second Pennsylvania gambling operator to offer online sports betting on Monday, effectively extending the reach of the Bensalem casino to every corner of the state.

The Pennsylvania Gaming Control Board said the first of three days of online testing for Parx would begin at 4 p.m. and go to midnight. Longer test periods are scheduled for Tuesday and Wednesday.

Rivers Casino in Pittsburgh is scheduled to become the third casino to offer online sports wagering on Tuesday, said Doug Harbach, a gaming board spokesperson. Rivers is owned by Rush Street Gaming, the company that owns and operates SugarHouse Casino in Philadelphia, which inaugurated online sports-betting in Pennsylvania in May. Since Rivers and SugarHouse operations share technology, Rivers will require only two days of testing before a full launch.

SugarHouse said bettors placed $573,163 in interactive sports bets during the last four days of May when its system was undergoing testing, according to the gaming board.

Parx began taking sports bets in January at its physical location, and also offers wagering at its off-track betting locations in South Philadelphia and Oaks.

With the launch of online sports betting, industry experts say, betting will grow dramatically in Pennsylvania. In New Jersey, customers placing bets on mobile platforms or from desktop devices now account for about 80 percent of the sports betting volume.

The sports betting lines and odds for Parx, SugarHouse, and Rivers are all managed by Kambi Group PLC, a European operator that recently opened its North American headquarters in Philadelphia.

Pennsylvania, New Jersey, and Delaware are among the first states to legalize sports betting since the U.S. Supreme Court decision a year ago that overturned a federal ban on sports betting outside of Nevada.