The World Wreckers (1971) - a "Darkover" novel by Marion Zimmer Bradley. This takes place last in the series [at least until Exile's Song and its sequels were written], and is one of several to feature Regis Hastur. In 1972 she wrote Darkover Landfall, which takes place first in the series. The "Darkover" series was a lifelong project for Bradley, and after bracketing the beginning and end of the series, she was free to write whatever sections of her version of a "future history" interested her most - for in the Seventies, Bradley was getting better and better with each book - The Forbidden Tower from 1977 was a Hugo-nominee.

Is it possible to murder a planet? The sinister, menacing Andrea, head of Worldwreckers, Inc.,, attempted to do just that - and for a fee. If a planet resisted colonization and industrializaion advances of the Terran Empire (exploitation), then a service like Worldwreckers, Inc. (known to the public as "Planetary Investments Unlimited") might be called in - to destroy the economy of the planet in question - so they would have no recourse but to turn to the Terran Empire to "pick up the pieces." Lord Regis Hastur becomes aware that someone is out to assassinate every remaining telepath on Darkover - and he resolves to stop this plot - by any means neccesary. He is willing to accept help from any source, including offworld telepaths, or surprisingly, the legendary teachers of the Comyn - the Chieri, who have come out of hiding, and ask for him by name.