"We have prepared a very good offer (...) we are just at this moment completing the offer," the chief executive office Jaime Guardiola told analysts during a conference call.

A total of 775 million pounds in grants is up for sale for smaller lenders in Britain, part of cash the UK government and European Commission ordered RBS to provide following its 45.5 billion pound state bailout in 2008.

Guardiola also said the bank was considering selling its Solvia real estate manager and promoter.

(Reporting By Jesús Aguado; additional reporting by Emma Rumney; editing by Paul Day)