DUBLIN, Sept. 30 (Xinhua) -- The Irish manufacturing sector maintained a strong growing momentum in August despite a decline in profitability, according to the latest Investec Manufacturing Purchasing Managers' Index (PMI).

The PMI, a widely used index for measuring the country's manufacturing activities, showed that the Irish manufacturing PMI rose to a seven-month high of 57.5 in August from 56.3 in July.

The expansion of the sector was mainly driven by growths in output and new orders, said Philip O'Sullivan, chief economist with Investec which compiled the index.

New order growth quickened to the fastest in the year so far, with strong demand reported from both domestic and export markets, he said, adding that the rate of expansion in new export orders was the highest in three months with Britain, the Eurozone and the Middle East as main sources of the new orders.

Given the strong growth in new orders, it is no surprise to see further increases in the backlog of work which grew to the highest since March, quantity of purchases which rose to the highest since December and employment indices, he said.

The current sequence of job creation in the Irish manufacturing sector has now extended to 23 months, he added.

Despite its strong growing momentum, the Irish manufacturing sector witnessed a seventh successive decline in profitability in August due to the rising costs for a range of raw materials such as metals and timber, said O'Sullivan.

The forward-looking future output index remains very elevated and reached a three-month high in August, he said, adding that 56 percent of the manufacturers expect a rise in production over the coming 12 months with just 4 percent of them anticipating a decline.

"With a positive economic backdrop both in Ireland and abroad, we think this optimism is well-founded," he said.

A mark of 50 of the PMI separates expansion from contraction.