During a court session attended by CEO Micky Arison, Carnival agreed to pay $9 million in fines and to contribute $9 million to environmental organizations. It also agreed to overhaul environmental-safety practices on its ships and at Carnival port facilities around the world.

Miami-based Carnival's crosstown rival, Royal Caribbean Cruises, the No. 2 cruise operator, paid $27 million in fines and penalties in the late 1990s to settle ocean-dumping complaints in Florida, California, Alaska, the Virgin Islands and Puerto Rico.

Prosectors last week said engineers aboard the Carnival ships had repeatedly discharged into the Caribbean and other waters waste fluids from machinery, engines and shipboard operations which had illegally high concentrations of oil.

The engineers also illegally overrode sensors designed to prevent dumping of waste water containing more than 15 parts per million of oil, and falsified logs on waste discharges, according to prosecutors.

"It's bad enough Carnival was polluting our and international waterways. What's worse was that they were lying about it," U.S. Attorney Guy Lewis told reporters. "It was literally saving the company millions of dollars."

Lewis, who said Carnival's executives had cooperated fully with the investigation into its environmental practices, also said that Carnival had pledged to hire environmental watchdogs for all its ships and facilities and to put in place senior executives to ensure high environmental-safety practices.

"What this really amounts to is a change in the way Carnival does business," Lewis said.

A spokesman for Carnival said executives and staff at all levels had been interviewed by investigators and that the company had turned over 1.5 million pages of records and documents during the investigation.