A court in Paris has convicted French oil company Total of "maritime pollution" over France's worst oil disaster in 1999.
The Erika went down in the Bay of Biscay in December 1999
The tanker Erika sank 75km (45 miles) off the coast of Brittany, leaking 20,000 tonnes of oil into the sea.
Fuel contaminated 400km of coastline after the tanker broke up on 12 December 1999.
Total was fined 375,000 euros (£280,000) and ordered to pay a share of nearly 200m euros in damages.
The fine was the maximum penalty allowed.
The Erika's owner, Giuseppe Saverese, and its manager Antonio Pollara, were also found guilty, as was Rina, the Italian company that declared the Erika seaworthy.
Up to 75,000 birds died in the Erika oil spill
Total and 14 other defendants went on trial in February 2007. All denied responsibility.
There were scores of plaintiffs in the trial, including the French government, local councils and environmental groups.
Total was acquitted of a separate charge of complicity in endangering people and property.
The Erika was a 25-year-old rusting, Maltese-registered tanker that broke in two in heavy seas in the Bay of Biscay.
Its 26 crew members were winched to safety by helicopter, but two weeks later its cargo of heavy fuel oil began to wash ashore.
Up to 75,000 birds died in the spill.
A year after the sinking, the EU brought in tighter maritime safety controls, including the removal of single-hulled vessels such as the Erika.