Royal Bank of Scotland (RBS) has moved one step closer to reaching a settlement with all five shareholder groups that brought compensation claims against the lender in connection with its 2008 rights issue.

The bank said on Thursday that it has reached a "full and final settlement" with a further 9% of total claimants, which represent part of the fifth and final shareholder group that has yet to resolve the dispute.

Those claimants are estimated to have received around £80 million of the £800 million pot that was put aside by the bank to cover the claims.

However, the bank stressed it made the payments "without any admission of liability".

Having settled this further portion of the rights issue claims, RBS said it had now "reached a resolution" with shareholders representing 87% of the claims by value in the litigation, leaving 13% of claims unresolved.

RBS has put aside an extra £10 million in provisions in light of the legal costs that claimants have faced since December.

However, the extra cost has already been taken into account and is not expected to weigh on first quarter results, set to be released on Friday.

RBS reached settlements with four of the shareholder groups in December 2016.

The legal action is linked to a rights issue overseen by disgraced former boss Fred Goodwin.

In April 2008, RBS asked existing shareholders to inject £12 billion into the firm to strengthen its reserves after the bank had spent £49 billion to acquire Dutch bank ABN Amro.

The deal proved toxic and, just months later, the value of RBS shares plunged 90% and the Government had to step in.

Chief executive Ross McEwan said: "We have been very clear that putting our legacy issues behind us is a priority so that we can focus on building the best bank for our customers, shareholders and employees.

"We are pleased to have reached this agreement. We will continue to explore the possibility of settlement with the remaining claimants but if we cannot settle on agreeable terms we will defend the claims at trial."

But the bank is not out of the woods yet, and could now face a parliamentary inquiry into spiralling legal costs - set to hit £125 million - used to defend itself, Mr Goodwin and three former directors in the rights issue case.

Members of the the RBS Shareholder Action Group who have not reached a settlement with the bank will be taking their case to trial next month, in what is becoming one of the most costly civil defences in British history.

A spokesman for the RBS Shareholder Action Group said that the vast majority of its members have already rejected a settlement with the bank, having followed legal advice, which suggests that the value of each share claim is 246p.

He said that those who have settled received 43.5p per share claim.

RBS is set to release first quarter results on Friday, with most analysts expecting underlying profits to more than double to £942 million, up from £440 million a year earlier.

It will come just over a week after Chancellor Philip Hammond's stark admission that the Government is prepared to sell its near 73% stake - bought for £45 billion in 2008 as part of a bailout at the height of the financial crisis - at a loss to the public purse.

The Government purchased its stake at £5.02 a share, though RBS stock is now trading at around half the price.

Cost-cutting is therefore expected to remain a key theme at RBS.

Results will likely be flattered by a strong quarter for its private banking arm and personal and business banking division.

The group is also hoping for a reprieve from the European Commission, which is mulling over a plan to spare RBS being forced to sell off 300 Williams & Glyn branches in return for state aid.

There are fears, though, that the alternative £750 million plan - meant to boost banking sector competition - may end up costing RBS more than the branch sale.

RBS is also yet to agree a potentially mammoth settlement with US authorities over mortgage-backed security mis-selling.