Mohegan Sun lost out on another casino license Tuesday when Pennsylvania gaming regulators awarded the remaining Philadelphia license to Stadium Casino LLP, a partnership that plans to build a $425 million Live! Hotel & Casino in the city’s stadium district.

The setback wasn’t nearly as stinging as the one Mohegan Sun suffered a couple of months ago in Massachusetts.

“We’d heard the rumors that Live! was going to get it, so we couldn’t be terribly surprised,” Mitchell Etess, the Mohegan Tribal Gaming Authority’s chief executive officer, said shortly after the Pennsylvania Gaming Control Board’s unanimous vote. “We’re disappointed. We know we did a very good job.”

Failing to win the Greater Boston license hurt more, he said.

“We had far more involvement in Boston. That was our show,” Etess said of the $1.1 billion resort casino Mohegan Sun had hoped to develop at the Suffolk Downs racetrack in Revere, Mass. “This (Philadelphia) wasn’t as big a financial commitment, but it would have been a great project for us. It’s very difficult to explain. You’re sitting there and you deeply believe that you have the best plan for the city and you can’t quite understand the outcome.”

The seven-member gaming board, which met at the Pennsylvania Convention Center in Philadelphia, did not immediately discuss the rationale behind its vote.

“This was a challenging decision involving four substantial proposals, but in the end we all felt that the Stadium Casino project best fit the intent of the Gaming Act and was best overall for Pennsylvania,” William Ryan Jr., the board’s chairman, said in a statement.

In Philadelphia, Mohegan Sun was involved in a partnership known as Market East Associates, whose principals included Philadelphia-area investors. The partnership’s $500 million proposal would have been built downtown at Eighth and Market streets.

Etess said Mohegan Sun would have contributed $20 million to the project if it had won the license.

Mohegan Sun has pursued gaming licenses in jurisdictions outside Connecticut because of growing competition in the Northeast gaming market. In addition to projects in Massachusetts and Pennsylvania, where it operates a casino in Wilkes-Barre, Mohegan Sun has proposed a casino in New York’s Catskills region and last week expressed interest in northern Connecticut.

Stadium Casino LLP is a joint venture between Greenwood Gaming & Entertainment LP, which operates the Parx Casino in Bensalem, Pa., and the Cordish Cos., which operate both the Maryland Live! Casino near Annapolis, Md., and the Xfinity Live! entertainment complex in Philadelphia. The other applicants for the Philadelphia license were Tower Entertainment and PHL Local Gaming LLC.

The license that eluded Mohegan Sun was held at one time by a partnership that included the Mashantucket Pequot Tribe’s Foxwoods Resort Casino, which won it in 2006. The Foxwoods Casino Philadelphia project failed to materialize, however, and the gaming board revoked the license in 2010 and sought a new round of proposals two years later.

SugarHouse Casino, whose developers also won a Philadelphia license in 2006, opened in 2010. Its owners had urged the gaming board not to license a second casino in the city, citing saturation in the market.

b.hallenbeck@theday.com

Twitter: @bjhallenbeck