"We're not going to change this overnight, it's not going to happen in the (March 20) budget," Vince Cable said at the Retail Week Live conference.

"But what would be very helpful would be to have a proper debate with the industry and the government and others about how the taxation of commercial property should operate," he said. "I would like to open up a much bigger debate as to whether we've got the tax base right.

Cable acknowledged that there were serious problems with the current system, which is linked to inflation, noting "all kinds of hidden distortions".

Business rates are taxes to help pay for local services, charged on most non-domestic properties, including shops, offices and factories. They are set by government.

Cable said he was sympathetic to calls for chancellor George Osborne to extend business rate relief for small shops beyond April 2014 in his budget speech next week.

The British Retail Consortium wants the coalition government to go further, freezing overall business rates in April 2013 and then delivering a system for the future that produces increases that are more affordable.

Last week Cable questioned the coalition government's focus on debt cutting in the most explicit terms he has used so far, saying it may be time to borrow to invest in infrastructure.

Osborne is under heavy pressure to revive an economy that risks sinking into its third recession in four years.

Consumer spending generates about two-thirds of Britain's gross domestic product, but job insecurity and a squeeze on incomes has put shoppers under pressure, pushing music retailer HMV, camera store Jessops and DVD rental firm Blockbuster into administration this year.

(Reporting by James Davey; editing by Guy Faulconbridge)