Rehabilitating bond guru Bill Gross’ tarnished reputation required an explosively worded, $200 million lawsuit against the company he founded, PR guru Michael Sitrick confesses in his recently released book, “The Fixer.”

That lawsuit would be the “ideal platform” for getting Gross’ “complete story to the public” after months of being depicted as “erratic, imperious and a liability,” Sitrick writes.

Many remember when Gross shocked the investment world in September 2014 by abruptly resigning from PIMCO, the firm he co-founded, following reports of in-fighting with the asset manager’s heir apparent, Mohamed El-Erian.

A year later he would sue PIMCO, claiming he was forced out by a “cabal” of greedy execs clamoring for a piece of his compensation.

But instead of claiming the expected $200 million for himself, Gross said proceeds would go to charity, another sign that Gross’ focus was on “setting the record straight,” Sitrick writes in the entertaining 278-page tome.