BRITAIN's hard-pressed factories have received a surprise boost after registering an improvement in output in January thanks to a rise in computer manufacturing.

Monthly output for the manufacturing industry rose by 0.3 per cent, according to data from the Office of National Statistics (ONS).

The ONS said the increase was accounted for by a seasonally adjusted 24.1 per cent rise in computer production from a weak December performance.

But economists warned that stripping out the progress made by the computer industry, manufacturing output would have fallen in January.

Manufacturing showed an overall decline of 0.5 per cent in the latest three-month period - November to January - with a 2.5 per cent fall in the transport equipment industries and 2.3 per cent in the machinery and equipment industries.

Rising computer output could not save the overall production figures which showed that manufacturing is now 0.9 per cent lower than the same quarter a year ago.

The ONS added that its wider measure of industrial production, which includes mining, quarrying, and electricity and gas output, fell by 0.8 per cent in the same three-month period.

ONS data also showed that Britain's trade deficit deteriorated due mainly to rising imports rather than falling exports.

The deficit on trade and goods in January was £3.3bn compared with a deficit of £3bn in December.