As Deutsche Telekom's shares slip closer to their initial issue price, the man widely identified with the emergence of a popular shareholder culture in Germany risks becoming a symbol of its shortcomings.

To Ron Sommer's critics, Deutsche Telekom's difficulties are increasingly the fault of its chairman's poor judgment. Such is the public anxiety - three million Germans own Telekom shares along with a large number of Irish investors - that even Mr Gerhard Schr÷der, the chancellor, felt obliged to intervene. "Naturally I am concerned about the current development of the share price," he said last week. "I'm convinced that Telekom is a business whose shares are trading below their proper value at present."

Mr Sommer is not willing to shoulder the blame. In a telling contrast to Mr Jeff Skilling, who this week quit as chief executive of Enron, the US energy trading company, the 52-year-old executive has defiantly sought to deflect personal criticism.

The trigger for the latest sharp fall in Telekom's stock was a decision by Deutsche Bank to intermediate in the sale of a block of it. The bank's disregard for traditional German corporate solidarity was a "serious professional mistake", Mr Sommer said. To underline that, he took out full-page newspaper advertisements defending his corporate strategy.

His falling reputation is a striking reversal for a man with what seemed the perfect pedigree to run Europe's biggest telecommunications group. Fluent in French and English, Mr Sommer cut his teeth at Nixdorf, a German computer company, before working his way to lead Sony Europe in 1993. Two years later, he was picked by the German government to revitalise Deutsche Telekom, a bureaucratic and overstaffed organisation preparing for privatisation.

His background was suitably cosmopolitan for a group with global ambitions. Born into a Russian-Hungarian family in Israel, Mr Sommer grew up in Vienna, where he earned not only a mathematics degree but also a doctorate by the age of 21.

Even his private life fits the textbook combination of family man and dedicated manager. At press conferences, he keeps his mobile phone switched on in case his wife Ingrid or his two sons ring. In spite of an immense workload, he tries to leave Telekom's Bonn headquarters in time to eat supper at his home in a Cologne suburb, taking work home if necessary.

A combination of strong personality and corporate experience has won Mr Sommer admirers. "The change in corporate culture that he has created, in transforming a former public sector institution into a high-performing company, is phenomenal," says Mr Edward Cumming-Bruce, a banker at Dresdner Kleinwort Wasserstein, which has handled transactions for the group.

But Mr Sommer's perfectionism, his obsession with order - his office is immaculate - and his reluctance to delegate have made him enemies, especially among those pushed out of their jobs in his seven years at Telekom.

And in spite of his aura of cosmopolitanism, he is not seen as a successful deal-maker in a business where international alliances and takeovers have often proved crucial. A botched attempt to merge with Telecom Italia in 1999 behind the back of Michel Bon, head of France Telecom, cost him his alliance with the French group and forced Deutsche Telekom's exit from its Italian joint venture. Even VoiceStream, the US mobile phone group bought this year, was a second best after a failed rapprochement with Sprint.

The VoiceStream deal is at the heart of Mr Sommer's difficulties. Negotiated in 2000, when valuations for telecoms assets were sky-high, the $27.9 billion (€30.5 billion) cash and shares deal has left nearly 200 million Telekom shares with former VoiceStream investors. Much of the stock is expected to flow back to the market in coming months, depressing Telekom's share price and raising more doubts about Mr Sommer's future.

Mr Sommer has seemed to be on the verge of being ousted before, only to emerge reinforced. In 1998, the German finance ministry, backed by a small group of Telekom executives, seemed poised to stage a coup, blaming his over-optimistic profit targets and underperforming share price. Rumours of a departure resurfaced last year, just before Telekom's supervisory board extended his contract for four years.

Deutsche Telekom's status as Germany's first mass privatisation and the fact that the state owns 43 per cent of the stock means Mr Sommer's tenure is likely to remain a matter of political, as well as private, interest as long as its shares remain weak.

There is a shared belief that Telekom's problems cannot be pinned on a single person. For that reason - and the absence of an obvious successor - Mr Sommer's job may be safer than his critics wish.

But with every decline in the share price, the formerly dashing leader cuts a humbler figure.