The Independent/Amba Student of the Year: And then there were four...

The shortlist for this year's competition is an international affair. Peter Brown looks at each of the candidates

Most good MBA classes are diverse and multicultural. All the students are usually competitive, driven and effective. Picking the stars among them is no easy task.

The judges in the MBA Student of the Year competition, now in its 11th year, are forced to look for evidence of that extra something that sets a student apart from his or her peers, and this year's finalists do not disappoint.

The competition, run jointly by The Independent and the Association of MBAs (Amba), is designed to highlight the value of the MBA, both to businesses and to individuals looking to broaden their knowledge or step into new areas. It highlights the all-round contribution required of a MBA student. Academic achievement is, of course, vital – but not enough on its own.

The award is one of the ways Amba advocates the benefits of an MBA and champions the achievements of accredited schools – finalists are nominated from students at Amba's accredited schools, and this year 58 entered.

"We were delighted to see a very diverse group of candidates this year, and an increased number of accredited business schools nominating a student for the first time," says Jeanette Purcell, chief executive of Amba. "As with previous years, the standard was extremely high, and our panel of judges had a very tough job in selecting the four finalists from the shortlist of ten."

Last year's winner, Bart Knols, 43, from Holland, had visited Kenya aged 19 to study sleeping sickness, and vowed to devote his life to tackling insect-borne diseases: malaria kills a child every thirty seconds. Knols's MBA from the Open University Business School helped him to pioneer an entirely new method to control mosquitoes, using a fungus, which since 2006 had attracted more than $2m (£1.2m) in research funds, with projects in Ghana, Kenya, Tanzania and South Africa.

This year's candidates come from all the corners of the globe. Kagisho Mahura, 35, did his MBA at Stellenbosch Business School, near Cape Town in South Africa, where he was class representative. In 2006, competing with two colleagues against 28 American schools, Mahura won the National Black MBA Association Case Competition held in Atlanta, Georgia.

With 10 years' business experience under his belt, he is currently chief executive of Bomang Capital, a consulting and investment company. He is building a wealth management business aimed at serving the "under-serviced black affluent market" in South Africa.

"The MBA has enhanced my desire, ability and confidence to manage my business," he says. He knows the pressures an MBA can bring: "While I was studying we had a baby and I started a new job, which put my wife Pheladi under tremendous pressure."

Mahura takes most decisions, he says, from a spiritual point of view. He is convinced that South Africa can only be built into a leading nation if people start talking about issues that make them uncomfortable.

Tony Sadownichik, aged 48, completed Rotterdam School of Management's executive OneMBA programme, on which he started a leadership panel for sustainability and economic growth.

He grew up in Vancouver, where he explored the local mountains and felt a connection with "the complex eco-systems that sustain us". He says he has come full circle, from identifying mining, fishing and forestry opportunities for KPMG, to forming sustainability strategies with Greenpeace, for which he is head of international research in the Netherlands.

This year Sadownichik has pioneered Greenpeace's entry to the European Space Agency consortium that monitors the global environment. It is the first NGO to be admitted.

"The breadth and depth of the interaction I had with the other MBA participants, and the richness of those encounters, really helped me in negotiating with the Space Agency," he says. His goal is to find ways of integrating eco-diversity with economic objectives.

Gajender Sharma, 34, graduated this year from HEC in Paris, where he was president of the MBA Council, as part of which he raised £20,000, created two new professional clubs and developed a networking partnership. He also organised a two-day Net Impact conference on corporate social responsibility.

Born in India, where his father moved every three years from one state to another, Sharma realised how hard families struggled to provide education for their children. He studied mechanical engineering at Delhi before spending five years working in Japan.

At HEC he won leadership, marketing and branding awards. He is now an associate consultant with AT Kearney and has founded an organisation called Positive Drive that seeks to create sustainable projects to decrease poverty and improve child education worldwide.

Mamta Singhai, aged 28, finishes her executive MBA this December at Strathclyde Business School – convenient, since she also teaches engineering at Strathclyde University. She recently won a Women Engineering Society Prize and looks set to graduate with a distinction.

Born in Massachusetts to parents of Indian origin, she was brought up in Scotland and describes herself as "a citizen of the world". Diversity, she believes, "does not dilute our identity but simply enhances it".

As a young female in the business world it is often difficult to be treated equally, she says, and the MBA has gone a long way towards redressing that, boosting her confidence in all areas of business. As a child she saw discrimination against immigrants and grew determined never to be disadvantaged because of her cultural background. She says she always wants to win.

The winner will be announced at a gala dinner in London in November