By Patrick Bartlett BBC Europe business correspondent

Shares in the German telecommunications firm Deutsche Telekom have plunged a day before a boardroom bust-up is expected over the fate of its boss, Ron Sommer.

Investors were reacting to reports that the government of Chancellor Gerhard Schroeder, which owns 43% of the business, wants a Telekom insider, Gerd Tenzer, to take over the top job.

Gerd who?

Many of Telekom's 3 million investors blame Mr Sommer for mounting debts and a huge slump in the company's stock value.

Just two months before national elections, and amid mounting shareholder anger, the centre-left government has decided Mr Sommer must go.

Arguably the country's most controversial business leader, Mr Sommer masterminded Deutsche Telekom's privatization in 1996, before launching a hugely ambitious strategy of international expansion.

The resulting debts and stock market jitters have driven the company's shares down to just one tenth of their peak value, two years ago.

Poisoned chalice

But Chancellor Schroeder's search for a successor has been fraught with difficulty, not least because Mr Sommer is fighting hard to keep his job.

Big name industrialists appear to have shied away from a position regarded as a "poisoned chalice".

Sommer: still standing

Reports that the government has picked an internal candidate whom few ordinary shareholders have heard of provoked the latest share collapse.

The government will seek backing for Mr Tenzer at a supervisory board meeting on Tuesday.

It seems likely it will succeed, given that half the seats on the board are held by normally trade unions that normally support the government.

Political factor

The debacle has taken centre stage in the German election campaign with the opposition leader, Edmund Stoiber, seeking to use it as yet another example of the government's alleged economic incompetence.

Mr Stoiber said on Monday that Mr Tenzer was by no means the ideal candidate.

Telekom staff, meanwhile, have reacted with dismay, taking out newspaper adverts last Friday, attacking what they called "attempts to turn the firm into a political football".