A significant US investor in the Shannon region has cautioned that if wage levels in Ireland were to rise again in line with levels of recent years, it would have to re-examine its investment here.

John Cooper, chairman and chief executive of Nasdaq-quoted technology firm Avocent, which employs 160 people in the midwest, said its Irish operations had successfully transitioned from being a low-cost manufacturing base to a "relatively high cost" administrative and engineering centre over the last 10 years.

When the company established its operations here in 1995, about 75 per cent of its activity was manufacturing, but it does almost none now.

"Your Government has done an excellent job," Mr Cooper said, "but it is important that your politicians exercise restraint right now and do not give in to the pressure of giving short-term benefits to their constituents when they could trigger long-term problems." He was speaking ahead of yesterday's company agm which was held at Avocent International in Shannon. This was the first time it was held outside the company's home base of Huntsville, Alabama.

Mr Cooper said Ireland still had a number of advantages to offer US companies over other locations that compete for investment, including a low corporate tax rate and an "innovative" workforce. One of Ireland's most noticeable strengths was its immigration policy compared to other EU countries.

"An immigrant population makes the workforce more vital," he said. "At a macro level it shows a good attitude by the Irish Republic to allow qualified immigrants into the country."

Mr Cooper said he was concerned over the possible loss of flights into Shannon once the Open Skies agreement came into place. Avocent operates a customer demonstration centre in Shannon which it brings customers from Europe and Asia to visit; executives also travel regularly between Shannon and the US headquarters.

"The loss of flight services into Shannon wouldn't cause me to change things very quickly but over time, as you make [ investment] decisions, it could be a contributory factor."

Avocent specialises in helping companies to manage their IT operations and infrastructure. It employs more than 1,800 people worldwide. In its most recently reported quarter it had profits of $15 million (€10.9 million).