Activity in the country's manufacturing sector grew for the tenth month in a row in December.

The NCB Manufacturing Purchasing Managers index stood at 51.4 last month.

This was down from November's reading of 52.4 but still above the key level which signifies expansion.

NCB said that although the PMI still showed an improvement in operating conditions, the reading was the lowest since August.

Both the consumer and investment goods sectors posted production growth, while intermediate goods producers saw a decrease in output last month.

The index shows that new export orders were strong in December and expanded for a third month in a row. New export orders have now grown in nine of the previous ten months with companies reporting growing demand from the US as a factor in December's growth.

NBC also noted that increased workloads led firms to take on more staff, which made December the tenth successive month in which employment levels have grown.

Companies also said that the rate of input cost inflation remained sharp last month, with firms highlighting increased energy and fuel costs. Rising input costs led manufacturers to increase their charges after a marginal fall in November.

Philip Sullivan, the chief economist at NCB, said that higher fuel and energy costs continue to be a headwind for the sector, pushing input prices higher for the fifth consecutive month.

''Output prices remain restricted by competitive pressures but increased in December and look to be getting a little firmer. Output prices have now increased in three of the last four months,'' he added.