State-rescued Royal Bank of Scotland's net profit grew in the third quarter, as a gain on the sale of US unit Citizens eclipsed restructuring and misconduct costs, it said Friday.

Earnings after taxation climbed 6.2 percent to £952 million ($1.45 billion, 1.33 billion euros) in the three months to the end of September, compared with the equivalent part of last year, RBS said in a results statement.

However, pre-tax profit before exceptional items and restructuring costs more than halved to £842 million. That missed expectations for a profit of £988 million.

RBS chalked up a hefty one-off gain of £1.15 billion from the reduction of its stake in US division Citizens. The group aims to sell its remaining 20.9-percent holding by the end of the year.

Restructuring costs meanwhile stood at £847 million, as the group's corporate and institutional unit -- home to most of its investment banking activities -- slashed its countries of operation from 38 to just 13.

As a result, revenues shrank 16 percent to £3.05 billion in the reporting period.

The group also revealed costs of £129 million for the quarter relating to mortgage-backed securities litigation in the United States.

The latest results come after the British government recently trimmed its RBS holding from just under 80 percent to below 73 percent in early August.

The Edinburgh-based lender was rescued with £45.5 billion of taxpayers' cash at the height of the global financial crisis in the world's biggest banking bailout.

The group, under the leadership of chief executive Ross McEwan, launched a massive overhaul in February that slashed its investment banking activities and axed thousands of jobs.

RBS meanwhile warned on Friday that it could face rising legacy and restructuring costs in the coming months.

"In the fourth quarter of 2015, we expect restructuring costs to remain high as we continue to implement our core bank transformation and disposal losses to be elevated within the overall guidance on disposal losses, although the timing and quantum of these losses are subject to market conditions," the bank said.

"Whilst legacy issues continue to be addressed, material further and incremental costs and provisions in respect of conduct and litigation related matters are expected, and could be substantially greater than the aggregate provisions RBS has recognised."

In common with many other major banks, RBS has faced huge fines and compensation demands for its alleged role in the manipulation of foreign exchange market and Libor interest rates.