The move backfired when Barclays staff shopped the RBS workers to the regulator. The Office of Fair Trading said RBS executives broke competition law by giving their counterparts at Barclays information on how it priced its loans to professional services firms such as lawyers and accountants.
There is evidence Barclays used the information to set its own prices, but the bank escaped a fine because it reported the matter to the OFT.
RBS, 84 per cent state-owned after receiving a taxpayer-funded bailout at the height of the banking crisis, said that of the two employees involved, one had left the bank, while the other faced suspension and further investigation.
Ali Nikpay, the OFT director of criminal enforcement said: “Any company that discloses confidential future pricing information to its competitors risks a substantial penalty.
“It is important that companies operating in the UK understand the seriousness of such conduct and ensure effective competition compliance throughout their organisation.”
An RBS spokesman said: “This is a deeply regrettable and an isolated case from nearly two years ago.
“We have cooperated fully with the OFT throughout and have introduced stringent additional competition law training to ensure that this unacceptable behaviour does not happen again.”