WASHINGTON -(Dow Jones)- The World Bank is poised to win its first major funding boost in two decades, with members reaching a deal to increase its capital base by a third and give developing countries more power.

Country members of the poverty-fighting multilateral bank are emerging from a week of tough negotiations on the sidelines of the spring meetings with an agreement to inject about $86.2 billion in lending capacity, according to people close to the negotiations.

If approved by the bank's developing committee later Sunday, the capital increase would provide timely relief to an institution whose capacity has been stretched to the brink during the worst global recession since its creation at the end of World War II.

The World Bank would also better reflect the shift underway in global economic power toward fast-growing emerging economies, with China gaining one of the top ownership positions.

However, the U.S., which has traditionally been granted the bank's presidency, is expected to be able to maintain its veto power over major decisions despite giving up part of the additional holdings it would gain from providing capital.

"We can feel proud that we have concluded agreements on a transformative financial and governance reform agenda, along with new capital for the World Bank and a new and more representative shareholding formula," U.S. Treasury Secretary Timothy Geithner said in a statement.

Under the deal, the actual increase in paid-in capital increase would amount to $5.1 billion at the bank's International Bank for Reconstruction and Development, with $1.6 billion coming from the shift in shareholdings. But the IBRD, the bank's main lending arm, could call on a total of $86.2 billion from that paid-in amount, lifting the level of callable capital to $276.1 billion. Geithner said he will request required U.S. congressional approval for the increase.

The World Bank has already committed an unprecedented $105 billion in financing for developing countries since the crisis erupted in mid-2008, and it would be left with a lending capacity of just $8 billion a year after fiscal year 2012 without the capital increase.

World Bank President Robert Zoellick had warned that the failure to reach a deal would "allow it to wane in influence" and ill-equipped to cope with future funding demands.

Developing and transition countries, which would account for more than half the capital increase, would also boost their voting power by 3.13 percentage points to 47.19%.

However, anti-poverty organizations were still calling for more fundamental change. Elizabeth Stuart, senior policy adviser at Oxfam International, said the voting shift would still leave behind poorer countries, which only received "crumbs" out of the deal.

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