Mr John Thompson worked at IBM for 28 years before leaving to become chief executive of Symantec, the US-based internet security technology firm. Something of his previous employer still clings to him, in his sober manner, sombre dress and air of a corporate man.

He still thinks after the fashion of IBM, looking to the long term and emphasising the importance of research and technological development. Moving to a much smaller company has not narrowed his outlook and his ambitions for Symantec are on the grand scale.

"Europe represents a phenomenal market for us, hence our international expansion: we'd like to have a presence in 50 cities," he declares at the outset of the interview.

The company employs more than 300 people at a plant in Blanchardstown, Dublin, where it is engaged in manufacturing for all Symantec's non-US markets, including Europe and Asia.

At present, Symantec - with more than 100 million customers worldwide - derives 27 per cent of its revenues, which totalled $944 million (€1.03 billion) for 2001, from Europe. Given the downturn in the US market, Mr Thompson's planned sweep into Europe is based on the hope that it may prove more resilient. Symantec, with headquarters in Cupertino, California, makes software for virus protection, corporate firewalls, network monitoring, content and e-mail filtering, remote management and network security.

While some optimistic observers predicted earlier this year that makers of security software would prove immune to the malaise in the technology market, arguing that companies would always need security, such has not proved to be the case. The downturn has already hurt Symantec's revenue forecasts and growth rate.

Mr Thompson blames a softening consumer market, a strong dollar and some weakness at the lower end of the corporate market for his products. The higher end of the corporate market has been bearing up better, he says, although "there has been a slowdown in capital expenditure at some companies".

While other technology companies have been shedding staff in the face of worsening economic prospects, Mr Thompson is holding out. He says: "There will be no reduction of headcount, no lay-offs planned. I don't even want to think about it."

Amid the gloom, Mr Thompson sees opportunities for strong managers. He has, after all, been through several recessions in his 20-year career in the technology industry and expresses a wary confidence of weathering this one.

"I spent a small lifetime at IBM and I saw it go through the rise and recession of the late 1970s and early 1980s, the downturn of the early 1990s and then the revival of the second half of the 1990s. It is clear to me that companies and industries follow cycles, and it is the responsibility of leaders in companies to make sure that they have picked the market that will be most sustainable and robust in the long term."

The clearest opportunities in the downturn lie in acquisitions. Symantec has a long history of acquisitions, having completed 25 since its foundation in 1982, and will be looking for bargains as other companies fare badly. "I think we know how to do them - acquisitions - and they will always be part of how we move opportunistically into new markets," he says.

As well as seeking expertise from outside sources, however, he is keen to emphasise the role of internal research and development (R&D) efforts. He has raised the proportion of revenues spent on R&D from a historical average of about 14 to 15 per cent to 16 per cent and more.

That seems to reflect the lessons learned in his time at IBM. With its company motto "Think", IBM has always prided itself on the quality of its technology development, pursuing long-term scientific goals as well as short-term product work, and numbering several Nobel laureates among its researchers. The company's devotion to development and its long-term thinking have clearly made a big impression on Mr Thompson.

Economic downturns will not be allowed to stand in the way of his company's long-term goals, he has decided.

"If you become distracted by short-term micro- or macro-economic problems, you lose the chance of real leadership. And we are not going to be distracted now," he says firmly.

Another lesson learned from IBM is the importance of communicating with staff - easier in a company of 4,000 people than a behemoth of more than 316,000.

"The measure of a leader is the consistency of the communications; for example, remembering the appropriate venues to deliver a particular message.

"Remembering that you may have heard the message a dozen times, but the recipient may not have. The cadence of the messages allows people to become comfortable with the message over a period of time," he explains.

For all that - he has clearly thought long and hard about the nature of leadership - Mr Thompson seems slightly reluctant to take on one of the forms of leadership that many outside observers have been keen to foist on him. As the only black chief executive of a major US technology company - he joined Symantec in April 1999 - Mr Thompson seems ideally placed to act as a role model for the black community in the US. While he wants to encourage other aspiring chief executives, however, he does not trumpet such a job for himself.

"If my success provides an example to others, or opens doors to others, that is terrific, but I don't go to work every day with that objective. I go to work with the object of building the market - in the process, if there are ancillary benefits, that's good," he says, diffidently.

In the end, perhaps Mr Thompson simply does not want to have his role defined by other people. Although 28 years in a notoriously strong corporate culture have clearly made their mark, his decision to leave IBM showed a desire to break out and remake himself.

He had been talking for years about his desire to lead his own company, and his wife told him: "Either you do it, or you shut up."

Was it the right move, to Symantec? Despite the downturn, and the uncertainty of the future, Mr Thompson is clear. He smiles: "I'm damn happy."