Brazil’s state-run oil company Petrobras and investors got a U.S. court to sign off on a $3 billion class settlement resulting from a bribery scheme, the largest resolution of its kind in a decade.

“But the nearly $300 million in attorneys’ fees requested by plaintiffs’ counsel needs to be reduced by roughly one-third,” Judge Jed S. Rakoff wrote June 25 for the U.S. District Court for the Southern District of New York.

Counsel for objector William Haynes called the decision...