LONDON (Reuters)–- The British government is wasting large sums of money by failing to take advantage of its size and credit rating to get the best deals from suppliers, a retail tycoon said yesterday in a government-commissioned report.

The Conservative-led cabinet, which plans next week to announce £83 billion ($132.3 billion) of spending reductions over the next 4-5 years, said the report showed that greater efficiency could soften the impact of cuts.

Billionaire Philip Green, whose Arcadia Group owns the Topshop clothing chain, was invited in August by Prime Minister David Cameron to study government efficiency. He focused on procurement of goods and services like computers, travel and office supplies and the management of government property.

"The conclusion of this review is clear — credit rating and scale in virtually every department has not been used to make government spending efficient," said Green. "There is no reason why Government should not be as efficient as any good business."

Green said he was not going to place a total on the potential savings, but set out examples of tens of millions of pounds squandered through poor management of the central government's property portfolio.

"I think from this report it is clear that the prize for the taxpayer is too big and significant not to chase," he said.

Looking at the example of fixed line-telecoms, Green said that centralised purchasing could potentially save 30-40 percent on an overall bill estimated at £2.0 billion per year.

The Conservative-led coalition government took office in May, ending 13 years of Labour rule. It frequently accuses Labour of having mismanaged the economy and led the country to the brink of economic ruin.

Cameron's spokesman said action would follow the 33-page report, presented mainly in the form of a series of slides.

"We're going to follow up all the recommendations in the report," the spokesman said.

Green called for an audit of all contracts with more than £100 million of remaining value, saying the estimated overall total was £16 billion.

The review found that the data on where and how the government spends its money was of poor quality. A lack of a centralised approach to buying goods and services had allowed departments to pay hugely different prices for the same items.

Cabinet Office Minister Francis Maude met chief executives of the 19 biggest suppliers to the government in July to discuss efficiency savings.

"The scale of the waste uncovered by Sir Philip and his team is staggering," Maude said in a statement yesterday.

"Every pound that we can take out of the cost of government is a pound we can protect on the front line. Our over-riding aim is to protect the quality of front line services and to protect the jobs of dedicated public sector workers."