British Airways and Korean Air Lines were yesterday fined $300 million (€220 million) each in what the US Department of Justice said was one of the largest and most far-reaching price-fixing criminal conspiracy cases.

The announcement came hours after Britain's Office of Fair Trading imposed a record fine of £121.5 million (€180 million) on BA. The penalties are the first results of a series of global investigations and civil lawsuits over surcharges on aviation fuel that are causing the airline heavy financial and reputational damage.

The co-ordinated regulatory action - in cases in which a conspiracy involving other leading airlines is alleged - highlights the increasingly tough approach being taken on cartels internationally, in part because of US pressure.

Simon Williams, head of cartel investigations at Britain's Office of Fair Trading, said there was "a global trend to get tough on cartels". "There is a general feeling among regulators globally that people still don't get the message," he said. "This fine is part of trying to ram home the message that we are getting tougher on cartel behaviour."

Virgin Atlantic and Lufthansa alerted the US Department of Justice to the conspiracy and would avoid criminal convictions and hefty fines as a result, prosecutors said.

In the US case, BA and Korean Air agreed to each pay penalties and co-operate in an ongoing criminal investigation into three separate schemes that prosecutors said had increased passenger fares on long-haul flights and illegally raised rates for air cargo shipments.

BA pleaded guilty to engaging in two separate conspiracies to fix the price of air cargo shipments for customers in the US and around the world, and those of fuel surcharges on long-haul flights.