LONDON (AP) -- Cynthia Carroll will step down as chief executive of mining company Anglo American PLC after almost six years in the job, the company announced Friday.
Carroll, who is to leave the company as soon as a successor is found, made no reference to reports that some investors had lost faith in her leadership following a series of controversial events including a series of strikes in South Africa and a dispute in Chile. Earlier this month, the rating service Standard & Poor's lowered its outlook on the company from "stable" to "negative" because of the turmoil in South Africa.
"Of course, we always listen to our shareholders very carefully. However, today's decision is very much based on Cynthia's decision," Anglo's chairman John Parker said in a video interview posted on the website Cantos.
Anglo American shares rose about 3 percent to 1913 pence by early afternoon in London as investors hoped the change in leadership would benefit the company. "It will lead to speculation about a potential restructuring of the business or takeover," said Jonathan Jackson, an analyst at Killik & Co. in London.
Carroll, a 55-year-old American, was appointed chief executive in 2007. She was the first non-South African and first woman to lead the company.
"It is a very difficult decision to leave, but next year I will be entering my seventh year as chief executive and I feel that the time will be right to hand over to a successor who can build further on the strong foundations we have created," she said.
Trained as a geologist, Carroll started her career with Amoco. She joined Alcan in 1989, rising in 2002 to the posts of president and chief executive officer of Alcan's primary metals group.
Carroll will also be stepping down from her roles as chairman of De Beers, an appointment announced earlier this month, and of Anglo American Platinum.
Anglo American posted a record operating profit of $11.1 billion in 2011. In that year it paid $5.1 billion for the Oppenheimer family's 40 percent stake in De Beers, raising Anglo's stake to 85 percent.
In the first half of this year, operating profit slumped by 38 percent and net profit fell 70 percent as the group was hit by lower commodity prices and higher costs.
Anglo American also became embroiled in a dispute with Chile when it announced in 2011 that it had agreed to sell its 24.5 percent stake in Anglo American Sur, its copper assets in Chile, to Mitsubishi for $5.4 billion. That sale was challenged by Codelco, Chile's state-owned copper miner, which had an option to take a 49 percent stake.
Codelco and Anglo American resolved the dispute in August as Anglo reduced its holding in AA Sur from 75.5 percent to 50.1 percent, while a Codelco-Mitsui joint venture took a 29.5 percent interest.
Anglo American's operations in South Africa have been set back by labor unrest since September, when more than 10,000 miners at Anglo American Platinum's operations outside Johannesburg went on strike demanding 16,000 rand (about $1,800) in monthly pay.
Amplats, the world's top producer of platinum, insisted the strike is illegal.
The company fired 12,000 workers en masse earlier this month, drawing condemnation from the influential Congress of South Africa Trade Unions, COSATU. COSATU has called for a massive street protest Saturday in support of the dismissed workers, who have threatened to make the company's operations ungovernable if they are not reinstated.
Mpumi Sithole, a spokeswoman for Amplats, said Thursday that the company stands by its decision to fire the workers.
Andrew Meldrum in Johannesburg contributed to this report.