Mr Hoss, who is nearly 69, has had the job on several previous occasions. He survived a car bomb attack in 1987 in which one of his bodguards was killed.

His predecessor, Rafik Hariri, was an important figure in Lebanon's drive to reconstruct after its long civil war ended in 1990.

However, Mr Hariri announced on Monday that he would not continue in the job after a dispute with President General Emile Lahoud, who was elected last month.

Parliament Speaker Nabih Berri said that Mr Hoss had the support of 95 of the 128 MPs in the half-Christian, half-Muslim legislature.

'Challenges are many'

The BBC correspondent in Beirut, Christopher Hack, says Mr Hoss is a respected consensus politician, but there are concerns the departure of Mr Harari will lead to a period of uncertainty which could threaten financial confidence in Lebanon.

After his appointment, Mr Hoss said that his new government would begin by tackling Lebanon's big budget deficit and reforming the economy, applying severe austerity measures in the 1999 budget.

Christopher Hack: Hoss seen as very clean

"The challenges we have to face are many, primarily the budget deficit which will be discussed in our first meeting in addition to the economic and financial situation," he said.

"We will maintain the stringent fiscal policies adopted by the previous government in drafting our 1999 budget... Fears about the financial situation are all illusions."

Lebanon's budget deficit is currently 40% of expenditure