Last week his SOSventures announced a $5.1m (Euro3.86m) investment in Dublinbased Mapflow, a location and geographic information system (GIS) firm that makes software for the transport and insurance industries.

It is a sector that O'Sullivan knows well, being the founder of Nasdaq-listed MapInfo. "We invented that thing where you type an address into a computer and the map comes up", O'Sullivan explains.

O'Sullivan now joins the board of Mapflow as its executive chairman. He says his investment will fund R&D into products that, he says, "if successful will define a whole new category of capabilities" to help transport planners deal with urban sprawl and global warming.

His $100m SOSventures will be headquartered in Kinsale, Co Cork, and O'Sullivan says that further investments in the Irish and European software sectors are planned.

He says that despite the pressures of increasing costs of doing business in Ireland, it is possible to build a global software business based in Ireland.

"When you are ylooking at world-leading products you don't need that many engineers to have an impact. MapFlow could be a couple of hundred people, not several thousand, " he added. "On that scale we can operate well in Ireland."