LONDON (Reuters) - State-backed Royal Bank of Scotland said it will invest 700 million pounds ($1.1 billion) between 2013 and 2016 to improve its retail operations, looking to revive its flagging brands.

The bank, whose owns NatWest and Ulster Bank, said the money will be spent on branch refurbishments, to improve its complaints handling, to allow customers to open accounts more quickly and to simplify processing of mortgages.

($1 = 0.6609 British pounds)

(Reporting by Matt Scuffham; Editing by Steve Slater)