State lawmakers embraced gaming expansion early and late Wednesday, with the House of Representatives voting in the wee hours to approve both the Mashantucket Pequot and Mohegan tribes’ third-casino plan and a related bill calling for more off-track-betting sites.

About 19 hours later, the Senate, which had approved the third-casino deal two weeks earlier, signed off on the so-called “sweetener.”

Even as the tribes were hailing the House votes, detractors of the bill granting them the exclusive right to develop an East Windsor casino vowed to launch legal challenges once the governor signs the measure into law, as he’s expected to do.

In a vote recorded at 1:11 a.m. Wednesday, the House voted 103-46 in favor of Senate Bill 957, which the Senate had approved, 24-12.

Both MGM Resorts International, the Las Vegas-based operator building a $950 million resort casino in Springfield, Mass., and the Shaghticoke Tribal Nation promptly issued statements saying they would take to the courts to protect their interests.

About a half-hour after voting on Senate Bill 957, the House narrowly approved the “sweetener,” House Bill 6948, which was designed to garner support for 957. It authorizes six more off-track-betting facilities in the state, establishes an advisory council to coordinate bookings at certain entertainment venues and requires the commissioner of the state Department of Consumer Protection to adopt regulations for sports betting, which currently is banned by state and federal law.

The House passed the bill 77-72. The Senate later passed it 22-14.

Earlier Wednesday, a spokesman for Gov. Dannel P. Malloy said the governor would need to review the bill’s final language before deciding whether to sign it.

“There are families across the state breathing a sigh of relief tonight thanks to leaders in both chambers and from both parties,” Kevin Brown, chairman of the Mohegan Tribe, said in a statement issued after the House acted on SB 957. “With this vote, we have all demonstrated a commitment to protecting the state of Connecticut and the good jobs of its residents.”

Rodney Butler, the Mashantucket Pequot chairman, called the bill “one of the most significant jobs initiatives of the legislative session,” adding that “with more than 9,000 jobs at risk, legislators banded together to save an important sector of Connecticut’s economy.”

The East Windsor casino, to be built off Exit 45 of Interstate 91, is supposed to shield Foxwoods Resort Casino and Mohegan Sun, the tribes’ southeastern Connecticut casinos, from the competitive impact of MGM Springfield, a $950 million resort casino expected to open next year in Massachusetts, about 15 miles north of East Windsor.

Bearing a $300 million price tag, the East Windsor facility is expected to create more than 4,000 permanent casino jobs and an additional 2,300 jobs for the building trades during construction, according to the tribes. It is to encompass 200,000 square feet, with 2,000 slot machines and 50 to 150 table games. The tribes will pay the state a 25 percent tax on the gaming revenues, from both slots and table games.

Over the past 25 years, the tribes have contributed more than $7 billion to the state’s General Fund while paying a 25 percent tax on slots revenue generated by Foxwoods and Mohegan Sun.

Gov. Dannel P. Malloy reiterated his support for SB 957 soon after the vote. He had indicated weeks ago that it was the only casino-expansion legislation he would sign, perhaps dooming an alternative bill that called for a competitive-bidding process among casino operators, an approach championed by MGM Resorts International, the developer of the Springfield, Mass., project.

“I commend and thank both chambers of the General Assembly for keeping Connecticut jobs and workers at the center of this debate,” Malloy said in a statement. “Our state has a longstanding partnership and compact with the Mohegan and Mashantucket Pequot tribal nations who employ thousands of Connecticut residents in their casinos. I have been very clear that I will not sign a bill that puts these jobs at risk, and I look forward to reviewing this proposal.”

Uri Clinton, MGM Resorts senior vice president and legal counsel, said the casino-expansion debate is far from over.

“It appears that the legislature is intent on approving a no-bid casino in East Windsor,” he said. “As such, the State of Connecticut missed an enormous opportunity to put in place an open, transparent, and competitive casino process which could have resulted in as much as $1 billion in economic development, the creation of thousands of jobs, and a licensing fee paid to the state of up to $100 million. What Connecticut got instead was far less than that.”

“We will continue to vigorously advocate in the courts as we seek to protect the constitutional rights of any company hoping to do business in Connecticut,” Clinton said. “And that, ultimately, is what our goal has always been: We’d like the chance to compete to do business in Connecticut.”

In a statement, Richard Velky, the Schaghticoke chief, urged the governor to veto SB 957, saying that otherwise his tribe “will have no alternative but to seek court action declaring the bill unconstitutional.”

“We still have time — the governor can do the right thing and reject this hastily thrown together, unworkable bill that leaves hundreds of millions of dollars on the table, doubles down state debt and will cost taxpayers dearly in both the short and long term,” Velky said.

Both MGM Resorts and the Schaghticokes filed federal lawsuits over the state’s 2015 enactment of a law that authorized the Mashantuckets and the Mohegans to form a joint venture and to solicit casino site proposals. After a district court sided with the state in the MGM suit, the Schaghticokes withdrew their suit, which MGM had bankrolled. MGM appealed the decision in its suit to the 2nd U.S. Circuit Court of Appeals, where a decision in pending.

House Bill 6948 increases from 18 to 24 the maximum number of authorized OTB facilities in the state. Like those previously authorized, the additional facilities may offer wagering on televised horse racing and jai alai and provide other amenities such as food. Fifteen OTB facilities currently exist, including one in New London. The location of each new facility would be subject to approval by the host town’s legislative body.

Under the bill, an Advisory Council on Large Entertainment Venues would be established to coordinate events at facilities with seating capacities of more than 5,000 people and “address other issues related to operating such facilities.” The list of such venues includes Rentschler Field in East Hartford, the XL Center in Hartford, Dodd Stadium in Norwich and Webster Bank Arena and Harbor Yard Ballpark, both in Bridgeport.

The council’s membership would include representatives of large entertainment facilities and the casino-owning tribes.

While the House’s southeastern Connecticut delegation unanimously supported SB 957, the delegation split along party lines in voting on HB 6948. Voting for the "sweetener" were Democrats Christine Conley and Joseph de la Cruz, both of Groton, Emmett Riley of Norwich, Kevin Ryan of Montville, Chris Soto of New London and Diana Urban of North Stonington.

Opposed to the bill were Republicans Devin Carney of Old Saybrook, Holly Cheeseman of East Lyme, Doug Dubitsky of Chaplin, Mike France of Ledyard and Kathleen McCarty of Waterford.

During the evening Tuesday, the Senate passed a bill eliminating promoters’ responsibility to pay health care costs incurred by mixed martial arts competitors, a measure expected to boost the sport. Legislators representing Bridgeport and Hartford had sought the legislation.

b.hallenbeck@theday.com