The Irish manufacturing sector expanded at the fastest rate in five months in December as the weak euro boosted new export orders, according to a new survey.

The Investec Manufacturing Purchasing Managers' Index climbed to 54.2 in October from 53.3 in November, moving further above the 50 line denoting growth.

The sub-index measuring new orders hit a five-month high of 57.2 from 55.6 the previous month, while new export orders were at a three-month high.

Higher new orders led to a build-up of backlogs of work and continued employment growth in the sector, the survey showed.

"A key highlight of today’s report is the New Orders segment, where the rate of expansion quickened to its fastest pace since July," Investec Ireland Chief Economist Philip O'Sullivan said.

"The New Export Orders segment points to substantial growth in overseas demand, with respondents attributing some of this to euro weakness, which helped to secure more work from the UK in particular.