London Briefing: Critics of the powerful South African mining industry have long argued that its boardrooms are "too pale and too male". The surprise appointment last week of 49-year-old Cynthia Carroll as chief executive of Anglo American certainly addresses one of those issues.

But news that Ms Carroll has been chosen to head the world's third-largest mining group met with a distinctly mixed reception not only in the mining world but also in the City of London.

Analysts and industry insiders had been confidently predicting either Philippe Varin of steelmaker Corus or Miklos Salamon of miner BHP Billiton would take the top job at Anglo. Ms Carroll, an American, was never even in the frame.

Even after a swift google of her name revealed Ms Carroll to be a trained geologist who rose to head the most profitable division of the Canadian aluminium group Alcan, analysts were still asking "Cynthia who?"

Shares in London-listed Anglo American tumbled more than 1 per cent, wiping several hundred million from the stock market value of the group.

Not only will Ms Carroll be the first female chief executive of Anglo American, which employs 195,000 people in more than 60 countries, she is also the first non-South African to head the group and the first to come from outside its ranks.

All the more surprising, given that even among the ranks of conservative mining conglomerates, Anglo American is regarded as one of the stuffier colonial boy's clubs.

She also joins the City of London's most exclusive club - that of female FTSE 100 chief executives. When she takes over at Anglo American next March, she will swell its numbers to three, joining Dame Marjorie Scardino at the publishing group Pearson and Dorothy Thompson at the power group Drax.

Carroll has had a distinguished career at Alcan, which she joined in 1988 and transformed from one of the highest-cost producers of aluminium to one of the lowest.

She spent some time in Ireland with Alcan in the 1990s, when she ran its Aughinish Alumina subsidiary. From next year, she will be based at the mining giant's headquarters in London.

The fall in Anglo American's share price after news of her appointment might not merely be down to the mining industry's misogyny, however.

Anglo American's performance has lagged behind that of its peers and it has been accused of failing to cash in fully on the recent worldwide boom in commodity prices.

Although it has the cash, the group has seemed reluctant to launch any sizeable takeover moves and has instead been widely tipped as a takeover target. That speculation has mounted over recent months, particularly since the current chief executive, Tony Trahar, told the market of his intention to retire six months ago.

Brian Gilbertson, the incoming chairman of Russia's Rusal group, is believed by some to be plotting a reverse takeover move. Other possible bidders could include Rio Tinto, Xstrata or Brazil's CVRD. So Anglo American's willingness to break with tradition in appointing Carroll might just signal that at last it is willing to shake off its somewhat staid past and usher in the cultural change that is required.

And that more dynamic approach could just be enough to repel any bidders - or at least make sure they have a fight on their hands.

Corus disquiet

The takeover of Corus by India's Tata Steel might have been signed and sealed but it has yet to be delivered.

Although the Corus board has agreed the deal, there are growing signs of disquiet not only from shareholders, but also customers of the Anglo-Dutch steelmaker.

In a letter to the Financial Times last week Sir Anthony Bamford, who is head of the privately-owned earth-moving equipment maker JCB, said he was "saddened and disappointed" that Corus was rushing into the hands of Tata rather than leading the inevitable consolidation of the sector with takeover moves of its own.

Sir Anthony's view counts, not only because he is one of the country's most respected industrialists but also because JCB holds a 2 per cent stake in the steelmaker. It is also one of the group's major customers.

Corus shares are still trading above the 455p terms and the deal, which will create the world's fifth-largest steelmaker, needs the backing of holders of 75 per cent of Corus shares.

As rumours of a counter-bidder refuse to die down, Sir Anthony's outspoken comments only serve to increase the pressure on directors of Tata and Corus to sell the bid to the City of London.

Fiona Walsh writes for the Guardian newspaper in London