Mohegan Sun objected late Tuesday night to the way the Massachusetts Gaming Commission awarded a casino license to Wynn Resorts, asserting that the commissioners gave Wynn an unfair advantage by allowing the company to increase its traffic mitigation offer at the last moment. The increase won over a swing vote on the commission and helped Wynn land the license.

The commission brushed aside Mohegan Sun’s objection on Wednesday as it formally signed a licensing agreement with Wynn. Commissioner James McHugh, a former judge, suggested Mohegan Sun changed its proposal slightly as well, but his chief argument against the objection appeared to be its timing.

“In my view, the objection at 10 o’clock last night came too late,” he said, noting the presentations occurred early on Tuesday morning.

The presentations came about because the commissioners on Monday seemed stymied and wanted Mohegan Sun and Wynn to clarify the responses they filed on Friday to the agency’s license conditions. Two commissioners said they were looking for answers to their questions or insights on the responses.

Mohegan Sun followed those directions in its presentation to the commission, but Wynn went much further, significantly upping the amount of money it was willing to spend in an effort to alleviate traffic congestion in Sullivan Square. The company increased funding by at least $10 million and by as much as $30 million under certain conditions. The changes made by Wynn eased concerns that had been raised by Commissioner Gayle Cameron about the company’s original response to the licensing conditions. Cameron then became a supporter of the Wynn project. The commission ended up voting 3-1 in favor of Wynn.

In its objection, Mohegan Sun said the commission “changed the rules midstream and applied those rules to the benefit of only one applicant.”

Mohegan Sun said that if it had been given the same opportunity, it would have increased the number of operational and construction jobs at its facility to match the numbers put forth by Wynn. That would have meant Mohegan Sun would have increased its jobs pledge by 2,428, or 51 percent. The number of jobs the project would generate was the top priority of all four commissioners.

The Mohegan Sun objection was signed by Mohegan Sun CEO Mitchell Etess and Doug Pardon, a partner at Brigade Capital Management.

Steve Wynn did not fly into Boston to sign the license at the Boston Teachers Union in Dorchester. Robert DeSalvio, the senior vice president for development, took care of that chore and afterwards said he is already reaching out to Boston Mayor Marty Walsh to launch discussions about how to work together to address traffic and other concerns related to the company’s Everett casino proposal. Boston and Wynn have been at odds, with both sides accusing each other of acting irrationally or unfairly.

Walsh at one point stopped negotiating a mitigation agreement with Wynn and let the Gaming Commission impose terms on the city’s behalf. Those terms ended up yielding far less money for Boston than the city would have received under a deal the city negotiated with Mohegan Sun.

Walsh has threatened to sue the Gaming Commission, accusing the agency and Commissioner McHugh of bias in favor of Wynn. At a senior event in Dorchester on Wednesday, Walsh said he is keeping all his options open, but indicated he would sit down to talk with Wynn officials following his return from a 10-day trip to Ireland.

During the Gaming Commission’s deliberations on the casino license, McHugh criticized the traffic mitigation efforts of Wynn and ended up voting for the Mohegan Sun proposal. Walsh had little to say about McHugh’s vote. “At this point, nothing really surprises me about casinos,” he said.

Both Wynn officials and Walsh gave interesting nonanswers to questions about this fall’s referendum to do away with the state’s casino gambling law.

Walsh, who voted for casino gambling as a state legislator and has strong ties to unions who support casinos, declined to say how he plans to vote on the referendum. “I’ll see when I go in the voting booth,” he said.

Wynn, in an interview with CommonWealth earlier this year, said his company wouldn’t take part in the referendum campaign. But DeSalvio on Wednesday was less firm on that point, saying it’s unclear whether the company will get involved in the referendum fight.