In the lead-up to a summit of the seven-member South Asian Association for Regional Cooperation (SAARC), Indian Prime Minister Atal Behari Vajpayee has suggested a common currency as South Asia moves towards a goal of economic union by 2020.

But economists say that, while the intentions are admirable, the timeframe is unrealistic for nations whose economic relations are superficial at best and their diplomatic ties weak.

The South Asia group's biggest members, India and Pakistan, are making an umpteenth attempt at peace on a border they have fought over twice since independence more than 50 years ago.

Political analysts say increasing business ties would help deter Pakistan and India from another war but economists say the creation of a single currency -- and therefore a single interest-rate policy -- would be difficult in economies that vary widely.

"The region is not a suitable candidate for a currency union," says Nephil Matangi Maskay of the Nepal Rastra Bank in a recent paper he wrote for the IMF Institute, after an analysis of 20 years of South Asian economic data.

The political commitment for a currency union was lacking, the region was still turbulent and monetary cooperation should proceed at the more cautious pace that the rest of Asia was adopting, Maskay said.

Bangladesh's Foreign Minister M Morshed Khan has also said it was too early to decide on a single currency.