PASADENA, Calif. — Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, announced today that its Board of Directors has authorized an additional $400 million share repurchase program, which is twice the size of the previous authorization. Together with the amount remaining under the previously approved program at the end of the third quarter of fiscal 2021, the Company has a total of $563 million available for share repurchases.