David Cameron will on Thursday use the London Olympics to drum up business opportunities, on the first day of a series of trade and investment events to showcase Britain during the Games.

Dignitaries such as International Monetary Fund Managing Director Christine Lagarde and the heads of global firms such as Google's Executive Chairman Eric Schmidt are expected to attend the first of the business events later on Thursday.

Britain hopes to seal £1 billion of deals this summer as businesses capitalise on the Olympics, the first to be held in Britain since 1948.

"I believe the legacy of these Olympics can be about many more things as well as great sport - for instance, it can be about great business too," Cameron said in extracts of the speech he is expected to give at Thursday's event.

"Yes, I want medals for Britain. And there will be no more passionate supporter of Team GB than me. But I've got a job to do this summer. And a big part of that job is to get behind British business," he added.

Cameron is under pressure to turn around Britain's recession-hit economy. On Wednesday, data showed the economy shrank far more than expected in the second quarter, battered by everything from an extra public holiday to the euro zone crisis.

The government is also keen to assuage critics of the Games who say the event is too expensive at a time of strained public finances, by highlighting the business opportunities offered by the event and uses of Olympic venues after the Games have ended.

"As we welcome the world's best athletes, we also welcome the world's best companies - so that they can succeed, invest, and create jobs," Chancellor George Osborne said.