China knocking on door of IMF's major league, US wavers

(Corrects paragraph 18, changing to Asian Development Bank)

* Europeans aiming for yuan entry into SDR this year -sources

* China would be first emerging nation to join IMF currency basket

* U.S. and Japan more hesitant

* Keen to avoid AIIB re-run, U.S. stresses conditions, not timing

By Paul Taylor

BRUSSELS, April 2 (Reuters) - China is closer to joining the major league of reserve currencies with a deal possible later this year to include the yuan in the International Monetary Fund's unit of account, international finance officials say.

However the United States, where China's growing economic and political muscle is a source of strategic concern in Congress, is reluctant to add the yuan so soon to the basket of currencies that make up the IMF's Special Drawing Rights.

U.S. Treasury Secretary Jack Lew said after a visit to Beijing this week the yuan was not yet ready to join the virtual currency that defines the value of the IMF's reserves, used for lending to countries in financial difficulty.

"While further liberalization and reform are needed for the (yuan) to meet this standard, we encourage the process of completing these necessary reforms," Lew said in a speech in San Francisco on Tuesday.

The yuan, also known as the renminbi or RMB, is already the world's fifth most-used trade currency. Beijing has made strides this year in introducing the infrastructure needed to float it freely on global capital markets.

European members of the Group of Seven major industrialised economies - Germany, Britain, France and Italy - favour adding the yuan this year to the basket that comprises the dollar, the euro, the yen and the pound sterling. Japan, like the United States, is more cautious, the officials said.

The IMF's board will hold an initial discussion in May on China's request and a full five-yearly review of the SDR's composition will be conducted later in the year ahead of a decision expected in November, IMF officials said.

"The German side supports China's goal to add the RMB to the SDR currency basket based on existing criteria," Joachim Nagel, a member of the executive board of the German central bank, said last weekend at a high-level forum in Boao, on the southern Chinese island of Hainan.

The upcoming review could be a good opportunity to introduce the yuan into the basket, he said, adding: "We appreciate China's recent development and progress towards liberalisation."

Chinese Premier Li Keqiang asked IMF chief Christine Lagarde last month to include the yuan in its SDR basket, pledged to speed up its "basic convertibility" and said China hoped to play an active role in international efforts to maintain financial stability, state news agency Xinhua said.