Britain was the largest grant donor to the World Bank's fund for poor countries in the latest round, followed by the United States, Japan and Germany, as the traditional top four donors shuffled their rankings.
Becoming a top contributor to the World Bank's International Development Association, or IDA, gives a country added influence over the bank's development policies and leverage over how cash is spent.
Every three years, the World Bank passes the hat among its richer members to raise money for IDA, which gives grants or low-interest loans to the world's 82 poorest countries.
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After the last fundraising meeting in Moscow last week, the World Bank said it raised a total pool of $52 billion. But it declined to share individual contributions until March, once its board officially signs off on them.
For the first time, some of the money given to IDA came in the form of low-interest loans, not grants, as domestic budgets have been strained by a sluggish recovery from the global financial crisis. The World Bank said about $4 billion of the pool came in the form of concessional loans.
The 46 donor countries decided on a discount rate that would count a small portion of each loan as a "grant equivalent," to enable comparison among the pools of cash.
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Britain pledged about $4.6 billion (2.8 billion pounds) over the course of three years in grants, and another 500 million pounds in concessional loans, according to a ministerial statement last week.
The United States was next, with $3.9 billion in grants, a US Treasury spokeswoman said. She added that Washington will seek to increase its contribution as the federal budget for the next fiscal year is finalized.
Japan was the number three donor in terms of grants or "grant equivalent,'' after the United States and Britain, and it also pledged a large amount in the form of loans, according to a source familiar with the discussions.
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Japan declined to provide specific figures.
Germany was fourth, pledging $2.2 billion (1.6 billion euros) in grants, conditional on parliament's approval, the spokeswoman of the foreign aid ministry told Reuters.
The money will start getting used for IDA from July 1, 2014.
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The United States has given the most to IDA since the program began in 1960, followed by Japan and the United Kingdom.
However, the portion of the U.S. contribution has steadily fallen, from 22 percent in 1960 to just over 12 percent in the last replenishment in 2010. Britain was also the top IDA donor in the 2007 funding round.
In recent years, as rich donors have faced pressure to to deal with bloated budgets, the World Bank has also started to tap emerging market donors, including China and Brazil.
World Bank President Jim Yong Kim said last week emerging markets played "a very large role" in the latest funding round.