The publishers installed two Flexible Printing System (FPS) presses from manufacturer Goss last year in a £20m investment.

It was the first FPS installation from Goss in the world, as part of a brand new printing facility.

At a speech given during a joint US and Northern Ireland investment conference, INM chief executive Sir Anthony O'Reilly said further investment had been warranted due to the success of the facility.

Two additional press towers, one cold-set and one heat-set, are to be installed at the plant by early 2009. The new presses will be used to produce high-quality glossy magazines, with up to 120 pages in one pass.

O' Reilly said: "This additional investment further underlines INM's total commitment to Northern Ireland and total confidence in its ability to host large infrastructural projects alongside a well qualified workforce to make it a success."

INM's Newry plant runs alongside the company's flagship facility in Belfast. Both sites are capable of full-colour production.

Included in the newspapers printed at the two plants are the Irish Daily Star and the commuter freesheet, the Herald AM.