Marubeni's biggest acquisition catapults it into the top ranks of global grain merchants and puts it in pole position to meet rising demand from China, where anti-competition regulators are also casting their eye over the transaction.

In the United States, the sticking point for the deal is centered around the handling of business ties between Gavilon and grain giant Archer Daniels Midland, who jointly are the majority owners of Kalama Export Company, one of the biggest U.S. West Coast terminals.

The completion of the transaction, initially slated for September, won't take place until November, as officials in both the United States and China consider the anti-trust implications of the takeover, according to the sources, who spoke on condition of anonymity.

They said the delay had nothing to do with concerns over the concentration of ownership of American grain elevators or due to opposition towards a foreign company acquiring U.S. assets.

"It's just regulatory procedures. It's nothing significant," said one person familiar with the matter.

A Marubeni spokesman declined to comment.

TRICKY TO UNWIND

Gavilon's ties with ADM were known to Marubeni when it announced the purchase of the U.S. grain trader in May, but talks on the future of the relationship are taking longer than expected, another source said.

ADM and Gavilon each have a 45 percent stake in Kalama, a grain export terminal in Washington state that handled a quarter of all Pacific shipments in 2009. The remaining 10 percent share is owned by Mitsubishi Corp.

ADM is believed to have the right of first refusal on the terminal, giving it the option to buy Gavilon's share of the joint venture if the company changed hands, trade sources said.

With exports to China booming, the terminal -- recently expanded by 25 percent -- is a prize asset, all the more so because it is one of Gavilon's few export gateways.

Apart from Kalama and a seasonal export terminal on the Great Lakes, Gavilon's assets are largely domestic. It has about 320 million bushels of storage in the United States, ranking it third behind ADM and Cargill but ahead of global giants like Bunge and Louis Dreyfus.

In 2011, Gavilon accounted for only 1.2 percent of all U.S. wheat, corn, soybeans and barley shipments, according to data from trade intelligence firm PIERS.

"It's a pretty big deal because it's the only export asset that Gavilon really has. When you take that out of the picture, (the Gavilon purchase) really is a 100 percent domestic deal," said a U.S. grain export trader, asking not to be named.

Marubeni is more established overseas. It owns Columbia Grain, a Portland export facility, however, and accounted for 8.5 percent of U.S. exports last year, PIERS data show.

ADM, Gavilon and Mitsubishi all declined to comment.

CHINA AIM

With more West Coast export capacity, Marubeni can more easily meet surging demand for grains and oilseeds in China, the world's most populous country.

China's commerce ministry needs to approve the sale of Gavilon to the Japanese trading house since the deal creates one of the country's biggest suppliers of grain.

"We're expecting the Chinese regulators to sign off on the deal in November anyway, so (the U.S. delay) is no big deal," said one of the people.

China's commerce ministry hasn't responded to faxed questions on its review of the transaction.

Marubeni agreed to pay about $3.6 billion and assume about $2 billion in debt for the U.S. grain trader, putting the total transaction at $5.6 billion.

The Omaha, Nebraska-based Gavilon's shareholders include Dwight Anderson's Ospraie hedge fund, investor George Soros and Egypt's Orascom Construction Industries. (Additional reporting by Emi Emoto in Tokyo; Editing by Raju Gopalakrishnan)

• A Permanent Economic Emergency