Rising demand for cheap computers in emerging economies like eastern Europe, the Middle East and Africa is leading to a peak in demand for used machines, according to a new study by Gartner.

The increase in the availability of used computers is fuelled in part by recycling legislation that makes it more expensive to discard old PCs. But this is also is giving rise to an industry that exports PCs merely to evade recycling laws.

"The demand for secondary PCs continues to exceed supply, providing opportunistic but potentially lucrative opportunities for specialised intermediaries and resellers or vendors looking to resell used PCs," said Meike Escherich, principal analyst at Gartner.

Of the 152 million secondary PCs shipped last year, only 55 million were dedicated for reuse.

Import tariffs, high transportation costs and a drop in the price of new PCs, in addition to environmental evasion, are preventing used computers from finding buyers.

Gartner found that only one in six PCs dedicated for reuse ends up on a desk in a developing market.

Currently about eight per cent of the world's computers have had a prior owner, but this figure is rapidly increasing. For every two new PCs shipping this year, one used model will be resold.

For 2009 Gartner projected that the number of used PCs that will be shipping to increase to nearly 110 million.

In addition to an overall appetite for computers in emerging economies, demand has further increased because computers last longer these days.