There are signs of a breakthrough in the protracted casino negotiations between Suffolk Downs and Mayor Thomas M. Menino’s administration, as the two sides have agreed on the framework of a high-priced deal that will allow the track’s casino project to move forward to a referendum vote, according to two people with knowledge of the negotiations.

Though details remain to be finalized on paper, the deal will be the state’s richest casino host-community agreement to date, with payments to Boston dwarfing the $25 million annually that a rival developer, Wynn Resorts, has agreed to pay to Everett, one of the people said. The package would take a substantial slice from the Suffolk Downs bottom line, but offers a new selling point in the fierce competition for the coveted Greater Boston resort casino license: Less for us, more for the community.