Glencore has a week to decide on sweeter offer for miner Xstrata

Ivan Glasenberg, Glencore International's billionaire chief executive, has a week to decide on his biggest bet yet - whether to raise his US$31 billion offer for Xstrata or see his five-year effort to create the fourth-biggest mining company disintegrate.

Qatar's sovereign wealth fund, which has 12 per cent of Xstrata, ruled out accepting Glasenberg's current bid on Thursday. That means Glencore's takeover probably will fail unless Glasenberg raises the offer in time for a shareholder vote scheduled for September 7.

Glasenberg, a former accountant and coal trader who owns 16 per cent of Switzerland-based Glencore, has worked there since 1984 and became chief executive in 2002. He will make the final decision and will rely less on advisers as the deal nears conclusion, a person familiar with the matter said, declining to be identified because he was not authorised to speak about it.

"He's a pre-eminent trader, and don't traders always leave it till the last minute?" said Peter Davey, head of metals and mining research at Standard Bank. "He's never going to disclose his hand upfront. That's how he makes money. It leaves the door open for him to try a better offer."

Glencore has offered 2.8 of its shares for each one in Xstrata, below the 3.25-share level Qatar Holdings said it wanted to back the offer. Just 16.48 per cent of shareholders can block the deal because under Britain's takeover rules Glencore is prevented from voting its 34 per cent stake.

Other Xstrata shareholders including Knight Vinke Asset Management and Standard Life have also called for a sweetened offer. Glencore may have to raise its bid to three shares to strike a deal, Jefferies Group said last week.