The president of Boston’s biggest construction company has parted ways with a senior executive who was closely allied with Mayor Thomas M. Menino after learning that the executive was unwelcome in Mayor Martin J. Walsh’s City Hall, several people briefed on the departure said.
Suffolk Construction chief John Fish, whose company prospered under Menino, severed ties this week with executive vice president Peter Welsh, said an adviser to Walsh after a friend of the mayor indicated that Welsh would no longer have access to city officials.
The Walsh representative told Fish that “the door is open to everyone, but not Peter,” according to the adviser to the new mayor.
Welsh, who had been the top adviser to Menino before leaving City Hall to work for Fish in 2002, campaigned hard last year for Walsh’s primary opponent, Charlotte Golar Richie. He had also criticized Walsh, and the criticism made its way back to Walsh, according to two Walsh allies.
Two people close to Suffolk Construction executives said Welsh was fired, but a Suffolk spokeswoman and Welsh both denied he had been dismissed. Welsh and a Suffolk spokeswoman insisted the decision to leave the company was “mutually agreed upon” by Fish and Welsh, who had been Suffolk’s executive vice president for business acquisition.
“I think Mayor Walsh is great,” Welsh, who remains a close friend of Menino, said in a telephone interview Wednesday. “He’s a very compassionate human being, and I don’t think he does politics that way. He’s been very decent to me whenever I’ve talked to him.”
Fish was not available for comment, but Suffolk Construction spokeswoman Kim Steimle Vaughan said, “Peter was at a point in his career where he had begun to think about other opportunities, and after conversations with John, he decided it was time to move on from Suffolk.”
The Walsh administration had no comment on Welsh’s departure.
Welsh’s departure may be the starkest example to date of the fallout in the business community from the change at City Hall after 20 years of Menino. Welsh’s job in large part was to secure city approvals for Suffolk projects, wielding so much influence with the Boston Redevelopment Authority that the board would sometimes delay meetings to accommodate his schedule.
While Welsh was at Suffolk, the company emerged as the dominant construction company in Boston, managing billions of dollars worth of construction from bio-tech and high tech facilities to the $650 million development taking shape at the old Filene’s department store site in Downtown Crossing.
Fish, meanwhile, has been one of the most civically engaged business leaders in the city, leading the effort to bring the Olympics to Boston in 2024 and helping to set up the One Fund Boston to benefit Boston Marathon bombing victims, which has raised nearly $61 million. He has also pledged $5 million to restore White Stadium in Franklin Park.
Fish also assiduously courted Menino, hiring not only Welsh, but David Passafaro, another Menino ally and former chief of staff, as well as Menino’s son Tom and brother David. Passafaro, a vice president, is expected to remain with the company, as are Menino’s son, who works as a safety engineer for a related company, Liberty Construction Services LLC, and his brother, who is a laborer for the company, say Suffolk Construction officials.
Fish largely stayed out of the mayoral race, donating neither to Walsh nor his general election opponent, John Connolly, according to state campaign finance records. Fish told the Globe four months before the vote that he was remaining neutral. Over the years, Fish has given Connolly $2,500, but never donated to Walsh, records show.
Welsh, by contrast, campaigned hard for Walsh’s primary opponent, Golar Richie, saying in a Globe interview on Wednesday that he supported the former Menino administration official “big time.”
Walsh came into office in January promising a “new era of transparency” after years in which Menino exerted direct personal control over economic development, often negotiating with developers himself in his fifth-floor office. Political pundits predicted that Menino insiders such as Fish would lose clout with City Hall.
While avoiding direct criticism of Menino, Walsh pledged to overhaul the BRA and other agencies, sending his first warning shot in March when he laid off 14 BRA employees. Walsh eliminated the entire business development division Menino had created last year.
Walsh is now sending the message that Suffolk Construction is “not the only game in town any more,” said an adviser to the new mayor. “Are others happy because there appears to be a broader playing field? Yes.”
The circumstances of Welsh’s departure were confirmed by several people close to Suffolk executives and the new mayor. Some observers said Welsh should have known that his job was in jeopardy once Menino left office.
“What’s the saying — live by the sword, die by the sword? This is the law of the jungle,” said a former city official who is friends with Welsh.
But Welsh took at least one step to ingratiate himself with the new mayor after he took office.
He wrote a $500 check to the Walsh campaign in February.
Andrea Estes can be reached at andrea.estes@ globe.com.