John Thornton would reinforce HSBC’s China syndrome

It would not just be a case of one highly successful banker following another (Thornton was a star at Goldman Sachs, co-heading its London operation and developing its mergers business outside North America). It would fit with HSBC's push into Asia, particularly China.

While chief executive Michael Geoghegan has played down the report today saying "there's no plan at the current time to change anything", he has included a get-out clause: "Obviously, we keep things under review, we have succession planning..."

Green is HSBC's executive chairman. Traditionally, HSBC has promoted its chief executive to become executive chairman. While that was acceptable to the City in the past, we now live in an age when corporate governance weighs heavier than ever.

Despite Green's efforts to justify and explain his position in regard to Geoghegan, it was never clear as to who did what — a distinction that became more blurred when Geoghegan assumed overall responsibility for group strategy.

So HSBC will become as other large corporations. Of greater significance, however, than HSBC streamlining its organisational chart, would be the possible choice of Thornton.

He is bound to be the front runner. He's an HSBC non-executive director, and, at 56, he is younger than the other obvious internal candidate, Simon Robertson, also formally of Goldman (of the likely external selections, Lord Davies, the ex-Standard Chartered head and recently deposed government minister, springs to mind).

Thornton is an Asia specialist — he is a professor at Tsinghua University in Beijing, chaired Goldman Sachs Asia, and a director of Industrial and Commercial Bank of China, China Netcom and Hong Kong's Pacific Century Group.

When HSBC relocated Geoghegan to Hong Kong — the bank's old home — early this year, it signalled a shift eastwards (not for nothing was Geoghegan feted like a conquering hero when he went into HSBC's Hong Kong office on landing). Thornton's elevation of would further cement that leaning.

Where that would leave the company's head office in Canary Wharf, is a moot point. The chief executive and many of his senior executives and advisors are based in Hong Kong and the new chairman would be someone with enormous ties in China.

If Thornton does get the job, the argument for staying here will become even tougher to sustain.