By David Lawder

WASHINGTON (Reuters) -The International Monetary Fund said on Tuesday its executive board approved a proposal for a 50% increase in quota resources to be contributed by member countries in proportion to their current IMF shareholdings.

The proposal would largely follow a U.S.-backed plan that would enhance IMF lending resources but delay any IMF shareholding increases for China, India, Brazil and other fast-growing emerging market economies. But the IMF said the board requested an accelerated timetable for developing options to guide realignment of the Fund's quota formula by June 2025.

The IMF said the 50% increase in quota funding -- equivalent to about $314 billion at current exchange rates -- would not increase its overall lending firepower of about $1 trillion, but would shift the composition to more permanent resources.

Currently, the Fund relies on bilateral borrowing arrangements and pledges to a crisis lending fund called the New Arrangements to Borrow for nearly 60% of its lending resources. It said these would be reduced to maintain the Fund's current overall lending capacity.

The quota increase "will help preserve a strong, quota-based and adequately resourced IMF at the center of the Global Financial Safety Net," IMF Managing Director Kristalina Georgieva said in a statement.

"An adequately resourced IMF is essential to safeguard global financial stability and respond to members’ potential needs in an uncertain and shock-prone world," she added.

The plan still needs approval by the IMF Board of Governors, which includes representatives from all 190 member states, with a vote requested by Dec. 15. The proposal, which saw broad support during the IMF-World Bank annual meetings last month in Morocco, needs an 85% majority of the fund's voting power to be implemented.

(Reporting by David LawderEditing by Chris Reese and Alistair Bell)