Lord Coe is to continue his involvement with the Olympics beyond the closing ceremony as David Cameron's "legacy ambassador", the Prime Minister announced.
The twice-1500 metre champion and former Tory MP has won plaudits for his role in making the Games a success as the chairman of the 2012 organising committee, Locog.
He will now advise the Prime Minister on the best ways to secure long-term benefits for the UK and act as a roving ambassador to help secure deals for British firms.
The Government set a target of £13 billion as the economic boost of hosting the Games.
Number 10 said that Lord Coe would also be tasked with ensuring efforts to boost sporting, volunteering and regeneration effects were also kept on track.
Mr Cameron said: "Seb Coe has done a brilliant job delivering the best Games ever. Now I want him to help me deliver the best Olympic legacy ever.
"Legacy has been built into the DNA of London 2012 from the very beginning thanks to Seb. I'm delighted that (International Olympic Committee president) Jacques Rogge described our legacy plans as a blueprint for future Games hosts.
"I am determined to make the most of the economic opportunities on offer from hosting the Games - making sure that we turn these Games into gold for Britain. I cannot think of a better person than Seb to be our ambassador to the global market-place and make sure we achieve our ambitious legacy targets."
Lord Coe said: "In terms of delivering world class events, Britain is at the top of its Game right now. Capitalising on this within the UK and around the world is clearly a priority and I am delighted to be involved."
A ComRes poll for the People found 68% of people thought he had done a "brilliant job".Suggest a correction