Royal Bank of Scotland (RBS) has been whacked with a 5.6m pound fine by British regulators for failing to disclose details of trades handled by its investment banking division.The taxpayer-owned lender was accused of incorrectly reporting 44.8m transactions between November 2007 and February of this year, and altogether forgotting to disclose 804,000 between November 2007 and February 2012. The Financial Conduct Authority said 37% of transactions handled by RBS's investment banking arm and treasury department were inaccurately reported.It meant millions of trades in shares, bonds and a range of other financial products were never properly disclosed to the authorities. RBS faced a fine of up to £8.0m if the bank had not settled early with the British watchdog.The lender has been forced to spend a further £14.5m resubmitting incorrect reports and fixing its IT systems.An RBS spokesman said: "RBS fully cooperated with the regulator throughout the investigation. We regret the failings that were uncovered and have subsequently made significant investments to our systems and controls in this area." The bank's investment banking arm has been hit by a series of scandals including an involvement in LIBOR rigging which led to £390m in fines to British and US regulators.Meanwhile, RBS is expected to announce a new Chief Executive to replace outgoing boss Stephen Hester, as early as next week. RD