Royal Bank of Scotland is set to pay more than £500m ($780m) to US and UK authorities as early as next week to resolve allegations it manipulated benchmark interest rates, according to people familiar with the matter. The settlement between the US Department of Justice, US Commodity Futures Trading Commission and UK Financial Services Authority is in its final stages and could be announced on Tuesday. Key details are still being negotiated, including whether the government-owned bank will agree to a DoJ condition that a subsidiary plead guilty to a criminal charge. The bank could pay between £500m and £600m. In settling, RBS will be the third bank to admit to widespread manipulation of the London interbank offered rate and related rates. The terms of the settlement and breadth of allegations are expected to fall within those of the two previous deals but could reflect a tougher stance from the DoJ, which has battled criticisms that it has been too soft on banks and executives. In June Barclays agreed to pay $450m to resolve allegations it tried to manipulate interest rates and “low balled” its submission to paint a rosier picture of its financial health. The bank avoided criminal charges but top managers were ousted amid a political backlash. In December UBS paid $1.5bn, and its Japan securities subsidiary pleaded guilty to wire fraud, to resolve allegations that nearly 50 traders were involved in manipulating interest rates. The authorities are expected to allege that RBS traders sought to influence the bank’s submission to Libor panels to benefit their trading positions. The case will not involve allegations that the bank “low balled”, these people say. RBS has fired at least four people in connection with its internal investigation into the matter. Some of the allegations may be linked to the UBS case, in which authorities allege Tom Hayes, a former UBS trader, used contacts in at least four other banks, including RBS, and interdealer brokers, to move interest rates to benefit his trading position. Mr Hayes’ lawyer has declined to comment on the allegations. According to the DoJ complaint, Mr Hayes allegedly asked a RBS trader to move the bank’s Yen Libor submission several times in 2007. The RBS trader replied on one occasion, “yes u owe me they are going 65 and 71”. When RBS’s submission was 0.64 per cent, Mr Hayes sent a message to the trader saying, “They set 64! . . . thats beyond the call of duty!,” according to the US complaint.