Foreign minister G L Pieris said Sri Lanka was showcasing its advantages of location, free trade deals with key economies and human resources to draw investors in.
Mohan Kaul, head of the Commonwealth Business Council said already proposals have been received for airports, energy and manufacturing.
The Commonwealth is made up of countries of the former British Empire.
At least one business proposal may touch a billion US dollars he told reporters in Colombo.
About 450 business delegates from 65 countries including Canada, where the Prime Minister is expected to boycott the meet will participate in the forum, he said.
Delegates from countries outside the Commonwealth including China, will also attend, he said.
With Sri Lankan participants about 900 to 1,000 are expected to attend, he said.
Kaul said some of the business proposals are already being discussed with Sri Lanka's investment promotions office.
He said following a CHOGM in Malta foreign direct investmen