He said he had put a similar proposal to the Abhisit Vejjajiva government, calling for a fund board represented by officials from the central bank and Finance Ministry, the Budget Bureau and investment experts from the asset management sector.

The Democrat-led government did not go ahead with the idea.

"Such a fund should not be managed by the central bank alone. By nature, the central bank does not want to take risk," said MR Chatumongol, a former central bank governor and finance permanent secretary.

Finance Minister Thirachai Phuvanatnaranubala last week told the central bank to consider a sovereign wealth fund to invest in overseas projects.

A number of countries around the world, including China, South Korea, Vietnam and Singapore, operate sovereign wealth funds to manage excess government revenues or foreign reserves.

Thailand's foreign reserves are running at an all-time high of nearly $190 billion, compared with $172 billion at the end of 2010. Reserves have climbed in recent years thanks to inflows from trade and investment and moves by the central bank to stabilise the baht.

MR Chatumongol, speaking on the sidelines of the Fiscal Policy Office's annual economics symposium, stressed that Thailand's foreign reserves belonged to the entire country, not the central bank or the ruling government.