BA has been fined a total of £269.5m by the UK Office of Fair Trading (OFT) and the US Department of Justice (DoJ) for breaching competition laws.
The OFT fine was £121.5m while the DoJ imposed what it called a "criminal" fine of $300m (£148m).
BA had put aside £350m to cover the expected fines when it announced its annual results in May.
The fines arose from BA staff discussing changes in its fuel surcharges with rival carriers.
The two senior members of staff allegedly involved have since left the carrier.
Willie Walsh, BA's ceo, said he was "happy" now that the matter had been resolved.
He added: "I want to reassure our passengers that they were not overcharged. Fuel surcharges are a legitimate way of recovering costs.
"However this does not in any way excuse the anti competitive conduct by a very limited number of individuals within British Airways.
"Anti-competitive behaviour is entirely unacceptable and we condemn it unreservedly.
"We have a long standing competition compliance policy which requires all staff to comply with the law at all times.
"I am satisfied that we have the right controls in place. However, it is deeply regrettable that some individuals ignored our policy."
The OFT and DoJ investigations began after Virgin Atlantic revealed its role in the talks with BA staff.
As Virgin was the first to report the breach in rules it has immunity from any fines.
BA said it had "responded swiftly to the investigation co-operating fully with the OFT and the penalty has been reduced to reflect this."
It added that the OFT and DoJ would "continue with their criminal investigation into the conduct of individuals."
The DoJ said BA had agreed to plead guilty and pay the fine for its role in a conspiracy to fix the prices of passenger flights.
Attorney General Alberto Gonzales said: "The Department of Justice is committed to vigorous antitrust enforcement and will continue to bring to justice those who fix prices and thereby deprive the American public of the benefits afforded by a truly competitive market."
In a statement the DoJ said “passengers who flew on British Airways flights between the
United Kingdom and the United States during the charged period paid more for their tickets as a result of the illegal cartel.
"In 2004, British Airways' fuel surcharge for round-trip passenger tickets was around $10 per ticket.
"By the time the passenger conspiracy was cracked in 2006, the surcharge was nearly $110 per ticket - a 10-fold increase."
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