Press reports claimed that the deadline for offers was initially last Wednesday but has now been extended to allow bidders more time.
RBS declined to confirm whether or not this was the case or reveal how many bids it has received so far.
Analysts have put a price tag of between £5bn and £7bn on the insurance business, which includes the Direct Line and Churchill brands. RBS revealed that it was putting this division up for sale at its AGM in April at the same time as it unveiled its £12bn rights issue.
Zurich Financial Services is tipped to be the frontrunner in the race, although it declined to comment on whether or not it would be making a bid. American Insurance Group, Chinese firm Ping An Insurance, Italian insurer Assicurazioni Generali and Warren Buffett’s Berkshire Hathaway were all at one stage thought to be interested in buying the UK insurance business but are now believed to have pulled out of the race.
US insurers Travellers and Allstate may still be in the running.