London-based Tompkins PLC has purchased a controlling interest in Rolastar Private Ltd., a duct accessories manufacturer from Mumbai, India. Terms were not disclosed.

Tomkins officials said the market potential for India’s HVAC industry is excellent and with four manufacturing facilities and plans for two more, Rolastar is well positioned to tap it. Its Air Express division markets and installs air-distribution systems throughout the country.

Ruskin Co., Tomkins’ North American-based damper and louver manufacturer, is also investing in Rolastar, and officials from Ruskin will help manage its operations.

“Our goals with Rolastar are to match the speed of expansion of the India construction market by continually improving the speed of duct fabrication and installation,” said Ruskin President Tom Edwards.

Rolastar management will remain. Bill Stout Jr., president of Eastern Sheet Metal, which Ruskin purchased in 2006, will assist in updating equipment. Management with another Tomkins company, Texas-based diffuser maker Titus, will also be involved, officials added.