Banking giant Royal Bank of Scotland has disposed of its remaining stake in the WorldPay global payments business, it was announced Wednesday. The group sold the 20% interest for a gain of £160m, which it expects to record in its 2013 results. The transaction is subject to regulatory approval which is expected by the end of 2013.It was also today reported that the bank could face an investigation by the Serious Fraud Office over recent allegations by government advisor Lawrence Tomlinson it mishandled under-performing small businesses. "The only thing we're saying is that we're aware of the issue and we are monitoring developments," a spokeswoman for the Serious Fraud Office said. The share price fell 0.2% to 329.23p by 13:15. NR