The first auction will be launched early next month to sell off the spare hotel rooms that tend to build up in January and February.
Customers logging on to RF's website will be offered the chance to bid for individual rooms, short breaks and longer stays that become available.
RF will set a minimum price and a closing date for bids. Bidders will type in their offer for a room and be told immediately if it is the best offer. The system will then alert them by e-mail if they have been outbid for the room, and invite them to bid again if they want.
Sir Rocco, who earlier this year launched another web venture, the luxury food group Lobster.com, believes that RF will be able to sell hotel rooms at higher rates through the online auctions.
"We are a new company in the marketplace and have the benefit that e- commerce has been part of our strategy from the start," said Sir Rocco. "All hotels have times when they offer special rates, and this mechanism allows us to set a very clear price and develop a dialogue with our customers."
RF currently has four top hotels - including the Balmoral in Edinburgh and St David's overlooking Cardiff Bay - and is planning to open two more in the spring. It is also building a new luxury hotel in central Manchester, which is due to open in a year's time.
RF's website, established two years ago, has been a success, fielding 1.5 million hits a year.
Anwen Parry, the e-commerce expert at RF, says that this is the first time a hotel group has set up an auction site like this. Other hotel companies allow their spare rooms to be sold through more general auction sites, such as lastminute.com, on which the RF site has been largely modelled.
Sir Rocco is still in the market to expand his chain of hotels. Earlier this year he was in talks with Savoy Group about purchasing the Berkeley Hotel in London's Knightsbridge. However, the deal fell apart when they could not agree a price.