A group of five major banks unlawfully exchanged sensitive information on UK bonds, the British antitrust agency said.

The Competition and Markets Authority said Citigroup Inc., Deutsche Bank AG, HSBC Holdings Plc, Morgan Stanley and Royal Bank of Canada each unlawfully shared competitively sensitive information in chatrooms between 2009 and 2013, according to provisional findings announced on Wednesday.

Deutsche Bank and Citigroup have both admitted their involvement. Deutsche Bank will not be fined and any fine that Citi receives will be discounted. Fines will be issued to the other banks once a final conclusion is reached.

“This could have denied taxpayers, pension savers and financial institutions the benefits of full competition for these products, including the minimization of borrowing costs,” said Michael Grenfell, executive Director of enforcement at the CMA.