Carrier selling Westborough-based NORESCO to California firm

Westborough-based energy services firm NORESCO is set to be under new ownership.

Florida-based Carrier Global Corp. is selling NORESCO to California-based OPTERRA Energy Services, Carrier announced Monday. 

The deal was agreed to on May 18, according to Carrier second-quarter financial filing with the U.S. Securities and Exchange Commission. 

OPTERRA is a subsidiary of New York-based LS Power, a firm focused on development and investment firm focused on power and energy infrastructure.

OPTERRA said in a Monday announcement the acquisition will allow it to expand programs in the public sector and will expand its presence across North America.

Carrier’s announcement said the deal is expected to close shortly. The deal is structured as a stock sale, but specific financial terms of the transaction were not disclosed. 

The sale of NORESCO comes after Carrier sold heating equipment manufacturer Riello to Ariston Group for $440 million on July 1, Carrier announced at the time. Both Riello and Ariston Group are based in Italy.

In a second quarter earnings call on Tuesday, Carrier Chairman and CEO David Gitlin said both sales were part of its efforts to simplify its portfolio, as the company looks to focus on data-center HVAC and AI-enabled building management business.

Based in Westborough, NORESCO helps customers upgrade energy infrastructure and buildings to increase energy efficiency. 

Carrier purchased NORESCO in 2008. The company secured a subcontract that is part of a $104-million upgrade to a Federal Bureau of Investigation complex in March and a $252-million contract relating to modernization of industrial infrastructure at an U.S. Army depot in July 2025.

NORESCO moved its offices from One Research Drive to 1400 Computer Drive earlier this year, said Jess Newfell, director, strategic marketing at the firm, in April. 

EDITOR’S NOTE: This article has been updated to include information from OPTERRA’s announcement. 

Eric Casey is the managing editor at Worcester Business Journal, who primarily covers the real estate and banking & finance industries.