©Eyevine

Growing up in Morro do Adeus, one of Rio de Janeiro’s most dangerous favelas, she used to collect cans and other bits of scrap metal to pay for her school books. As a teenager she wrote letters on behalf of illiterate migrants and took on other odd jobs to help support her family, staying out of the way of the local drug gangs.

Now the 59-year-old is chief executive of Petrobras, Latin America’s biggest oil company with a stock market capitalisation of about $150bn.

Ms Graças Foster’s office, larger than her family’s old house, is full of pink orchids and boasts one of the best views of Rio’s picture-perfect skyline.

Her tale echoes the rags-to-riches story of Luiz Inácio Lula da Silva, Brazil’s hugely popular former president, and resonates to an extent with the personal histories of the 40m Brazilians who have been lifted out of poverty over the past decade.

Asked to discuss her personal achievements, though, Ms Graças Foster is uncomfortable and impatient. “People like to find an excuse for everything in life . . . I don’t accept this idea that difficulties in your past define your future,” she says.

She certainly does not want any pity. “I had a very happy childhood – well, a happy childhood.”

While her father was often out of work, her mother was “very disciplined”, keeping the family together and making sure their small house was always tidy.

Ms Graças Foster is equally dismissive about any fuss over her being the first female boss of Petrobras since the state-owned company was founded in 1953 – no mean feat, particularly in the testosterone-charged oil and gas industry.

“My female colleagues and other women I meet on the street or at the beach enjoy the idea of having a woman in power probably more than I do,” she says, after some consideration. But “power doesn’t come by itself, it comes with responsibility and it’s the responsibility I live with, which weighs on me, which wakes me up at two o’clock in the morning, takes me away from my friends, and makes me a more impatient and irritable person”.

Her sombre tone is understandable. In spite of discovering vast oil reserves off the coast of south-east Brazil in 2007, Petrobras is one of the industry’s worst-performing companies. Its shares have fallen almost 20 per cent over the past two years and in August – six months after Ms Graças Foster took over – the company reported its first quarterly loss in 13 years. However, analysts point out that there is little Ms Graças Foster can do to solve some of Petrobras’s biggest problems. The company’s rising foreign debt levels, for example, can partly be blamed on the recent depreciation of Brazil’s currency against the dollar.

And for many investors, the biggest burden on the oil producer is smiling in an official gilded frame hanging on the wall behind her. Dilma Rousseff, Brazil’s president, along with her government, Petrobras’s controlling shareholder, have made life difficult. Complex regulation of the distribution of future oil profits has slowed down exploration activities and tough restrictions on contracting foreign companies have been blamed for increasing the company’s costs.

Meanwhile, the government’s decades-long policy of keeping domestic fuel prices artificially low has forced Petrobras to import oil at a loss to meet the seemingly insatiable demand of Brazil’s new middle classes. In June the government allowed a moderate rise in petrol and diesel prices – the first increase since 2006.

“It would make sense to do more adjustments when the time is right,” Ms Graças Foster says, choosing her words carefully. However, she refuses to be pinned down on details. Tact, it seems, is key to running a state company, where the president is always looking over your shoulder.

But it is no surprise that Ms Graças Foster has only good things to say about Brazil’s first female president, whom she first met 14 years ago. After all, it was Ms Rousseff who gave her the job – one of several key positions in the government and state entities that have been awarded to women since she took office last year. “Demand for fuel is so great precisely because of what President Lula and President Dilma have done for Brazil, creating more social inclusion,” she says, using the word “presidenta” – a sign of allegiance to the ruling Workers’ party.

Like Ms Rousseff, Petrobras’s new chief executive has also gained a reputation for doggedness, straight-talking and putting her mostly male colleagues in their place. In fact, she says this is how the story of her difficult childhood first became public – something she now seems to regret. “I was in the middle of an argument with someone and they were telling me that some place was not fit for a woman to go,” she said. She blurted out the details of her own tough upbringing in response, she says – “I didn’t have the least bit of patience to listen to that.”

In previous interviews, she has chuckled about how her colleagues probably all prayed not to have her as their boss as she moved up the company’s ranks. At the presentation of the company’s investment programme in June, she laid out plans to cut costs across the company – “and I’m not just talking about the staff Christmas party”. No one laughed.

In person, she is far from the battleaxe some of Brazil’s ageing elite would like to make her out to be. She makes an effort to be friendly and make small talk.

When asked about the small plastic model of The Beatles on her desk, next to one of an oil rig, her face lights up. “I love them!” she says, explaining that her enthusiasm is down to the fact that her husband Colin, who also works in the industry, is English.

But just because she is approachable does not mean she is easily fooled – having worked in Petrobras for 31 years, she has gained an encyclopedic knowledge of both the company and the industry.

After graduating in chemical engineering, Ms Graças Foster joined as an intern, working her way up and around Brazil’s biggest company. She says the experience has made her a more “efficient” chief executive, as she understands the intricacies of how the company functions. “The downside is there is a certain intolerance on my side; I don’t want to listen to an idea because I already know it doesn’t work.”

The insider/outsider dilemma is one that is debated by management consultants worldwide, who each reach different conclusions about the pros and cons of hiring someone from within the company. Ms Graças Foster may be the perfect compromise – what Joseph Bower at Harvard likes to call an “inside outsider”.

While Ms Graças Foster has grown up inside Petrobras, her childhood experiences have also given her an outsider’s perspective – one that she has still not forgotten.

“I’ve been back many times,” she says, adding that violence in her community has only increased over the years. “The last time I went was about two years ago but I couldn’t even get close to our house because it was in the conflict zone.”

As part of efforts to reclaim Rio’s slums from drugs gangs, the police and the army launched an attack in 2010 on Complexo do Alemão, the favela which now contains Morro do Adeus, seizing grenades, sacks of cocaine and about 36 tonnes of marijuana.

“I go back just because I miss it, I really miss it,” she says. For many Brazilians who grew up in the favelas, their sense of community is hard to find elsewhere in the city. “There is no sadness, or if there was I’ve forgotten it,” she says, drifting off into thought, before jolting back to her new air-conditioned reality. “But the past has passed, right?”