Four banks fined more than £100m for past exchanges of sensitive information about UK government bonds

The largest fine went to Royal Bank of Canada, which will pay £34.2 million. Citi will pay around £17.2 million, HSBC £23.4 million and Morgan Stanley £29.7 million.

All the banks had their fines reduced because they settled. Citi got the largest discount after settling before any of the others.

A fifth bank, Deutsche Bank, received immunity for reporting its conduct to authorities.

Gilts are the UK’s name for Government bonds, which work like an IOU note that people can buy from the issuer.

The Government promises to pay the buyer back at some point and pay a set interest rate, allowing it to borrow money for public spending.

The CMA said the traders were trying to restrict or distort competition.

“The financial services sector is an integral part of the UK economy, contributing billions every year, and it’s essential that it functions effectively,” said CMA executive director of competition enforcement Juliette Enser.

“Only through healthy and competitive markets can we ensure businesses and investors have confidence to invest and grow – for the benefit of all in the UK.

“The fines imposed today reflect the CMA’s commitment to dealing with competition law breaches and deterring anti-competitive conduct.

“The fines would have been substantially higher had the banks not already taken unusually extensive steps to make sure that this doesn’t happen again.”

The CMA said the banks have brought in “extensive compliance measures” to guard against future wrongdoing.

Some of this was done before the probe started in 2018.

The incidents were between 2009 and 2013, when the Bank of England was buying gilts from the market in response to the financial crisis.

Not all the banks were involved during the entire period. HSBC’s last infringement was in 2010 and Morgan Stanley’s in 2012.

Traders at Deutsche and Royal Bank of Canada shared information with each other on the largest number of individual dates – a total of 41 days spread between November 2009 and April 2013.

The combined fines for all the four banks add up to £104,460,000.

In a statement, the CMA said: “Gilts are an important type of UK government bond that help to finance public spending.

"Investors in gilts lend money to the UK government and in return receive a steady and stable stream of cash interest payments.

“Healthy competition drives investment, innovation and growth, and it is important that competitors decide their price and strategies independently in order to ensure effective competition in a market.”