Simpson Thacher has continued to build out its Boston office, adding M&A partner William Lay from Kirkland & Ellis. Lay spent seven years at Kirkland advising on M&A and private equity transactions, including nearly two years as a partner.
His hire comes after the firm opened in Boston in May 2024, adding more than six lateral partners in the months since launch, as increasing numbers of international firms move to build their presence in the city.










