The Friday Interview:  Ted Kelly, Liberty Mutual.Visitors to Liberty Mutual's Boston headquarters are greeted in the monumental lobby by a giant message carved in stone above the reception desk,  Denis Stauntonwrites.

It reads: "With our policyholders we are engaged in a great mutual enterprise. It is great because it seeks to prevent crippling injuries and death by removing the causes of home, highway, and work accidents. It is great because it deals in the relief of pain and sorrow and fear and loss. It is great because it works to preserve and protect the things people earn and build and own and cherish. Its true greatness will be measured by our power to help people live safer, more secure lives."

This is Liberty Mutual's corporate creed and, for Ted Kelly, the company's Co Armagh-born chairman and chief executive, it is less an expression of public piety than the key to explaining why the company is now the sixth-biggest property/casualty writer in the US and the ninth largest in the world.

"Somebody asked me once what makes Liberty successful, and it's very simple - we've a lot of nice people working here. That's how we succeed," he told me when we met in his private conference room last week.

Kelly is a trim 62-year-old with a mischievous grin and a disarming line in self-deprecating humour. But it took more than being nice to turn this former mathematician from a modest background in the North into one of America's most successful corporate executives.

Liberty Mutual saw its business grow by 12 per cent last year, and Kelly insists that most of the company's growth is organic rather than through acquisitions.

"Acquisitions without organic growth don't work. If we acquire a company and things stay at the status quo, we will have paid too much for it because the belief is that you pay a premium for a company because you think you can run it better or more effectively. So, to us, there's no conflict between acquisitions and organic growth," he says.

"We run all our companies with local people. We don't send US people to run these companies. Don't forget the huge cultural aspects of insurance - insurance is a fundamentally middle-class product. The rich don't need it and the poor don't need it.

"And the rhythms of middle-class life in each country and those cultural nuances of doing business in each country are very important."

Kelly believes that the trend towards consolidation, which has dominated the international insurance industry for the past decade, is set to continue as globalisation becomes inexorable.

"Our fundamental belief is that, in five to 10 years, in the not-too-distant future, there'll be a large handful of global P&S [ property and casualty] companies - five to 10 who will set the standard," he says.

Born near Keady, Co Armagh, Kelly grew up in a family of 10 children, the eldest of whom was 16 when his father died.

After studying maths at Queen's University Belfast, he won a scholarship to attend Massachusetts Institute of Technology to pursue graduate research.

Somebody told him that if you trained to become an actuary, you got paid for taking exams, so he joined US health insurer Aetna shortly after he earned his doctorate. "I was 29 years old and I never had any intention of being in business. I didn't know anything about business but it just turned out to be a milieu that suited me," he says.

Kelly will be in Ireland next week to mark the 10th anniversary of Liberty Mutual's operations in Dublin and Belfast.

The company allowed its IFSC licence to lapse in 2005 and is now focused more on the domestic Irish insurance market.

The Belfast operation is part of a different branch of the company that writes software for the firm's worldwide operations.

Kelly is relatively relaxed about the subprime mortgage crisis in the US, describing it as a problem of leverage rather than credit which is unlikely to have "calamitous" long-term effects.

He sees the biggest threat to the insurance industry, not in hurricanes or a housing slowdown, but in commoditisation, as has happened in the airline industry.

"If we allow people to view all insurance carriers as equal, undifferentiated service, undifferentiated product, then the only way to compete is on price. There is no industry where pure price competition has led to a combination of economic success and customer satisfaction," he says.

"With deregulation and price competition, and the ability to buy online so quickly, if an airline in the US says, 'we're going to give you a little bit more service and charge you $5 more', nobody buys the tickets so you can't do it. But everybody's upset by the lack of service. They want service and they don't want to pay for it.

"That is the worst possible combination of circumstances."