The New London Democratic Town Committee on Tuesday endorsed its chairman, Bill Satti, to be a candidate for the 20th district state Senate seat, while Tony Sheridan, president of the Chamber of Commerce of Eastern Connecticut, told the chamber board in a letter that he won’t be running.

The seat recently became open when longtime state Sen. Andrea Stillman announced that she will not seeking reelection.

Satti, a lifelong New London resident, has worked for 17 years overseeing community affairs and public relations for the Mashantucket Pequot Tribal Nation. He served two years on the New London Board of Education, eight years on the City Council and twice served as the city’s ceremonial mayor.

“I have given a great deal of thought to the possibility of seeking the office, including discussing the matter with my family, several key benefactors, friends, and the Board of Directors at our meeting this past Tuesday. These discussions have led me to believe that the Chamber’s best interest is served by my not seeking nomination for the State Senate,” Sheridan said in his letter.

Likely Republican candidate Paul Formica, the first selectman in East Lyme, said Friday, “We are moving in that direction, and we most probably will make some sort of announcement in the next coming days.”