Mumbai: Three years after investing in Airpax Holdings Inc., Chicago Growth Partners and Norwest Equity Partners have agreed to sell the sensor maker to Sensata Technologies Inc., a group company of Boston''s Bain Capital LLC, for $276 million.

CGP said it decided to exit its investment after being approached by a number of strategic suitors earlier this year. The company expects to net a return of 4.3 times its initial investment on exit.

Airpax makes circuit breakers, fuses, power switches, thermostats, temperature sensors and other products. Its customers include the US military and companies operating in a wide variety of sectors ranging from telecommunications to recreational vehicles and from heating, ventilation and air conditioning to alternative energy.

The acquisition will bring Sensata 2,800 employees and seven engineering and production facilities in China , Japan, Mexico and the US. It will also generate $170 million in sales and about $30 million of Ebitda this year, said one source familiar with the business.

Chicago Growth Partners and Minneapolis'' Norwest Equity Partners acquired control of Airpax in 2004, when it was generating roughly $80 million of revenue, in a transaction approaching $78 million. The deal was backed with financing from GE Antares Capital, the company''s primary lender.

CGP and Airpax chief executive Dennis Karr, who will remain with the business, built value in the company through acquisitions and one joint-venture purchase.

Airpax acquired power inverter maker Dimensions Unlimited Inc. of White Bear Lake , Minn., in July 2006 for an undisclosed sum, and purchased ED&D Inc., an Oviedo, Fla., developer of control system technology, in July 2005. Airpax had also bought out another stakeholder in a joint venture with Sanken Electric Co. Ltd. in the past year.

CGP had hired Chicago investment bank Lincoln International LLC roughly three months ago to field offers for the business. Lincoln International managing director Eric Malchow ran the process assisted by senior vice president Sean Bennis, associate Brad Keyworth and analyst Chris Lee.