The Massachusetts Gaming Commission Thursday approved MGM Springfield’s request to delay opening a downtown casino until at least September 2018.

The commission agreed with MGM that opening a Springfield casino during a major overhaul of I-91 is bad for business. Some gaming board members said they preferred a flexible opening date, based on when highway work wraps up. MGM Springfield president Mike Mathis said the company needs a firm date for a number of reasons, including their construction schedule, attracting retail tenants, and booking conventions.

“If we pegged a 2018 opening date, and had the building open in December 2017, I wouldn’t be able to make a commitment to be part of that opening group,” Mathis says. “Everybody wants to be in the hotel when it’s fresh and new.”

The commission also signed off on agreement between the state historical commission, and MGM about use of historical properties and materials located on or near the casino site.