If ever there was a man who was suited to the task ahead, it would be Mr Bob Herz. On July 1st he takes over as chairman of the chief US financial reporting rule-maker, the Financial Accounting Standards Board (FASB).

He does so at a time when US rule-making, after the failure of Enron, is being called into question as never before but also when efforts to promote the convergence of harmonised worldwide financial reporting rules are gathering momentum.

Mr Herz has a simple-sounding task. He has to change the US tradition of being wedded to a mass of rules and convince the US that the principle-based approach pioneered in Britain and used by much of the rest of the world is the route to follow.

"People say: 'You must be crazy' to take on the job," he says. But his own personal assessment is different.

"I'm pretty bullish," he says. "We do have the opportunity to change the world. But it is going to take a lot of commitment and effort."

Mr Herz is well placed to carry through the task. His career as New York audit partner with PricewaterhouseCoopers (PwC) involved him in much work within the profession on the standard-setting side and he has been a part-time member of the International Accounting Standards Board (IASB) since its inception last year.

So he has a deep understanding of both sides of the divide and he is hugely supportive of efforts to bridge it.

"FASB is already in a partnership with IASB and major standard-setters, and IASB has talked about a more targeted convergence project. I'm supportive of that," he says.

The target is to bring together international accounting standards (IAS) and American rules (US GAAP). "The question is the time-frame," he says.

He has a genial, inclusive style and the arguments are on his side. But he has a lawyer-dominated society to deal with. He says he understands the US environment "where there has been such a proliferation of rules". It is a product of people wanting it that way, partly because of litigation and partly because they like the certainty of the rules.

But a rule-based system has what Mr Herz refers to as "a dark side", which means you can end up not with the "true and fair view" principle that powers the British system but instead with Enron, where rules are played up to the edge and disaster ensues.

"Clearly the events of last year have caused people to ask questions about almost every aspect of both the company reporting system and the capital markets system," he says.

However, he has to be wary of the reappearance of the old "Fortress America" view that US GAAP is best and the rest of the world had better fall into line.

"There are cultural issues and vested interests involved. The view in the US is that we need to learn from others, but the view is that IAS is not yet ready for prime-time," he says.

There are two reasons for this. The first is that international stocks are not a major part of the US capital markets. The US investment community is wary of change that might rock the boat.

The second reason is regulation. "I do believe that any financial reporting regime does require proper review and enforcement mechanisms," he says. These exist in both the US and Britain. But there is no global regulator, and financial reporting, audit quality and enforcement are very varied and often very weak around the world, says Mr Herz.

He also faces political pressure. The IASB is an independent body but the FASB has always faced greater pressures.

"Over the years the US system has been more political. Standard-setting always involves change and people don't like change. And, if things don't go people's way, they make their voices clear through Congress and they put money behind it. Standard-setters need to be independent," he says.

Mr Herz has a tough task but on his side is his unique understanding of the two cultures. He may have a solid New Jersey accent but when he was 15 his family moved to Argentina and he went to an English school, followed the English educational process and went to Manchester University which, then as now, had a strong accounting faculty.

Mr Herz's path was set.

The man who brought the IASB into being in its current role as global harmoniser was Sir Bryan Carsberg. Some 30 years ago he was professor of accounting at Manchester and Mr Herz was his prize student. Now that student has even greater prizes within his grasp.