The Finance Ministry will float up to 100 billion baht in six-year public savings bonds from May 17-21. The issue, paying an average of 4% per year, would be the largest of its kind in 13 years, said Finance Minister Korn Chatikavanij.

Subscriptions will be through branches of 12 commercial banks nationwide, with funds raised from the offering used to finance infrastructure projects under the Thai Khem Khaeng programme.

A savings bond issue last year proved wildly popular, with 120,000 investors snapping up 80 billion baht in bonds within a few days.

The first priority will be given to Thais aged 60 and over from May 17-18, with subscriptions open for general Thai investors from May 19-21. The minimum investment is 10,000 baht and the maximum 1 million.

Mr Korn said subscriptions would be on a first-come, first-served basis, with allocations to each bank based on its deposit base and branch network. Bangkok Bank, the country's largest, has an allocation of 20 billion baht, Krung Thai Bank 18 billion, and Kasikornbank and Siam Commercial Bank 14 billion each.

Chakrit Parapuntakul, the director-general of the Public Debt Management Office, said the bonds would pay interest of 3% per year for the first two years, 4% for the third and fourth years, 5% for the fifth year and 6% for the sixth year.

Interest will be paid twice a year, on May 19 and Nov 19. Investors can redeem the bonds starting six months after the issue date.