By Clara Ferreira-Marques and Sinead Cruise
LONDON (Reuters) - Anglo American's
A geologist by training, New Jersey-born Carroll ruffled feathers when, fresh from the aluminum industry, she became the first non-South African, the first woman and the first outsider to take the top job at Anglo in 2007.
Brushing aside suggestions she was pushed to leave, Carroll and Chairman John Parker, her long-standing supporter, said on Friday there had been "differences of opinion" with shareholders but the decision to step down was her own, as she approached a seventh year in a "very grueling and demanding role".
Carroll's efforts to streamline a miner with colonial roots that became a sprawling conglomerate, her campaign to cut billions in costs and efforts to shift Anglo's centre of gravity away from South Africa have won her support among investors. A campaign to improve ties with South Africa's government has also garnered plaudits.
But her relationship with investors became more troubled after big-ticket acquisitions like the Minas Rio iron ore project in Brazil - an early bid to diversify Anglo's portfolio - which became mired in cost overruns and delays.
Anglo has yet to give a final cost for the project it bought in a $5.5 billion deal at the top of the commodities cycle, but analysts say spending could rise to $8 billion from current forecasts of $5.8 billion, already twice original estimates.
"Institutional pressure has been building for some time to replace Cynthia, so the news will be welcomed," one of Anglo's 15 largest shareholders said.
"Ultimately, running Anglo is one of the toughest jobs around and, although Cynthia made a good start as CEO, the feeling is the company has gone backwards in the last two to three years."
Other investors also pointed to a mixed record at the top.
"Her strategic moves didn't always hit the mark. The acquisition of Minas Rio, promptly followed by a dividend cut, was a particular low point," another of Anglo's 15 top investors said. Anglo scrapped its 2008 dividend to preserve cash.
Crippling strikes in platinum and iron ore mines in South Africa in recent weeks have revived long-standing worries over Anglo's exposure to the country, aggravating concerns about a share price that has underperformed its peers.
Despite her cost cuts, according to analysts at Macquarie, under Carroll Anglo has lost one-third of its value on a U.S. dollar market capitalization basis and is now worth $25 billion less. Other major miners are worth at least the same as they were at the start of 2007.
Anglo's recent deals - including its decision to take control of diamond miner De Beers, raising its stake in Kumba Iron Ore
So far this year, Anglo stock has lagged the sector by almost 20 percent. Shares rose on news of Carroll's departure and at 1000 GMT were up 2.8 percent at 1908.5 pence, while the broader UK mining sector was down 0.5 percent. <.FTNMX1770>.
The board said it would not rush to pick a successor for Carroll and that the 55-year-old would stay in place until a replacement was appointed, which could take months.
"For whoever comes in, the challenge of Minas Rio and the challenge of restructuring the platinum industry in South Africa doesn't go away," said analyst Des Kilalea at RBC in London. "To some extent, it's probably the most difficult mining company to manage at the moment."
Industry analysts, industry sources and investors point to at least two likely successors for Carroll - Brazilian Alex Vanselow, the former chief financial officer of BHP Billiton
Parker - in a reference to a storm over Davis' pay, one of the highest on Britain's FTSE - said Anglo could not afford him.
Internally, analysts point to Chris Griffith, a well-regarded platinum veteran who was plucked from his job at the helm of Kumba in July to run Anglo American Platinum
A new name may not prove an immediate solution for Anglo's troubles, from cost pressures to Brazilian delays, even if analysts said the company could use the opportunity to review its involvement in South Africa as well as platinum and sell a stake in the costly Minas Rio project or write down its value.
The biggest challenge is expected to be South Africa, where strikes have spread to Anglo American Platinum (Amplats), the world's top producer of the precious metal. The unrest has revived talk of a spinoff of Amplats, in which Anglo currently owns an almost 80 percent stake - something Carroll has opposed.
Strikes have also hit Anglo's Kumba iron ore unit, which alone has accounted for almost half the miner's profit.
Kumba's Sishen mine has begun to ramp back up, but Amplats workers have not yet returned to the Rustenburg, Union and Amandelbult operations, which include some of its most labor intensive shafts, and those that have suffered deepest margin compression since 2008.
The group is expected to conclude a review of the platinum business by the end of the year.
(Reporting by Clara Ferreira-Marques; Additional reporting by Sinead Cruise, Kate Holton and Brenton Cordeiro; Editing by Jane Barrett and Philippa Fletcher)