Former prime minister Helen Clark has taken a leap in Forbes' 100 most powerful women list this year.

Clark, who heads the United Nations Development Programme, has jumped to 34th place from 50th last year.

German chancellor Angela Merkel  was number one for a second year in a row. Sitting behind her was US Secretary of State Hillary Clinton.

Earlier this year, Foreign Policy ranked Clark number one in a list of the 25 women around the world who hold considerable power but are relatively unknown.

Forbes described Merkel as the "iron lady" of Europe and the lead player in the eurozone economic drama that continues to threaten global markets.

"As Greece, Spain, Italy and Portugal have teetered on the brink of an economic collapse, she has vowed to do everything in her power to preserve the 17-country EU, the magazine said.

Brazilian President Dilma Rouseff was third in the magazine's 100 most powerful women of 2012.

Forbes has been ranking women who "adhere to the traditional classifications of power and those who have risen to the top of the social and cultural landscape" for nine years.

It covers women in fields of politics, business, media, entertainment and non-profits.

Among the list, there were 25 chief executives who control $984 billion in revenues and 11 billionaires.

It also featured entrepreneurs and 10 celebrities who are "philanthropic do-gooders" and "entrepreneurial go-getters".

Sixteen women enter the list for the first time, including singer Jennifer Lopez, Petrobras chief executive Maria das Gracas Silva Foster, and billionaire and widow of Apple's Steve Jobs, Laurene Powell Jobs.

Celebrities on the list included Lady Gaga (14), Shakira (40), and Angelina Jolie (66).

Queen Elizabeth II was in 26th place.

Top 10:

-  Angela Merkel, Chancellor of Germany

- Hillary Clinton, US Secretary of State

- Dilma Rousseff, President of Brazil

- Melinda Gates, Co-chair, Bill & Melinda Gates Foundation

- Jill Abramson, Executive Editor, The New York Times

- Sonia Gandhi, President, Indian National Congress Party

- Michelle Obama, US First Lady

- Christine Lagarde, Head of International Monetary Fund

- Janet Napolitano, US Secretary of Homeland Security

- Sheryl Sandberg, COO, Facebook

- © Fairfax NZ News

Comments