Singapore's non-oil domestic exports fell unexpectedly in May, dropping by 4.6 per cent over the same month a year ago as makers of electronics goods shipped fewer products abroad.

Economists had expected a smaller 1 per cent contraction las month, similar to the performance in April.

But electronics shipments declined by a larger-than-expected 13.2 per cent in May over a year ago, dragging down overall exports.

This was largely due to less demand for personal computer parts and disk media products, said trade agency IE Singapore on Monday.

Non-electronics exports rose in May over a year ago, but only by a marginal 0.2 per cent, the agency said.

The increase was led by pharmaceuticals, printed matter and food preparations.

On a month-on-month basis, non-oil domestic exports dipped 1.1 per cent in May over April. They had risen 1.1 per cent in April over March.