Tenneco Inc. will expand its Kettering operations with a $61.5 million investment and hire an additional 300 employees. The project fortifies Tenneco in Kettering, where it already is among the largest employers with 400 workers. “It’s a huge win for us,” said Gregg Gorsuch, Kettering’s economic development manager. The project comes as Tenneco realigns its manufacturing footprint. It will then transfer business to the ride control facility in Kettering. The Kettering plant — at 555 Woodman Drive — produces parts for the automotive industries. Tenneco officials were not immediately available for comment.