* Vice Admiral Aucoin to be stood down on Wednesday - source
* Aucoin was due to retire in September
* Four accidents in Asia involving Seventh Fleet this year
* Remains found in search for 10 missing sailors (Adds background on Seventh Fleet, context, comment from Japanese defence official, detail on body found, paragraphs 2, 8-14, 17; adds bullet points)
By Phil Stewart and Tim Kelly
WASHINGTON/TOKYO, Aug 23 (Reuters) - The U.S. Navy will relieve Seventh Fleet Commander Vice Admiral Joseph Aucoin after a series of collisions involving its warships in Asia, a U.S. official told Reuters, as the search goes on for 10 sailors missing since the latest mishap.
The move to replace Aucoin comes days after a pre-dawn collision between a guided-missile destroyer and a merchant vessel east of Singapore and Malaysia on Monday, the fourth major incident in the U.S. Pacific Fleet this year.
"An expedited change in leadership was needed," the official said in Washington on Tuesday of the decision to relieve Aucoin of his command.
The Navy declined to comment on any plans to relieve Aucoin, which was first reported by the Wall Street Journal.
The official told Reuters that Admiral Scott Swift, the commander of the U.S. Pacific Fleet, would relieve Aucoin, a three-star admiral, when the two meet in Japan later on Wednesday.
It was not clear when the formal announcement would be made.
Aucoin was due to step down next month, with Phillip Sawyer, deputy commander of the Pacific Fleet and a submariner by trade, slated to succeed him. Aucoin came up through the Navy's air wing as an F-14 navigator.
The Seventh Fleet, headquartered in Japan, operates as many as 70 ships, including the U.S. Navy's only forward-deployed aircraft carrier, and has around 140 aircraft and 20,000 sailors.
It operates over an area of 124 million square km (48 million square miles) from bases in Japan, South Korea and Singapore.
TENSE TIMES
The accident involving the USS John S. McCain and the tanker Alnic MC in the Singapore Strait came at a tense time for the U.S. Navy in Asia.
This month, the John S. McCain sailed within 12 nautical miles of an artificial island built by China in the disputed South China Sea, the latest "freedom of navigation" operation to counter what the United States sees as China's efforts to control the contested waters.
An official Chinese newspaper said on Tuesday the U.S. navy's latest collision shows it is becoming an increasing risk to shipping in Asia despite its claims of helping to protect freedom of navigation. this month, North Korea threatened to fire ballistic missiles towards the U.S. Pacific territory of Guam in a standoff over its nuclear and missile programmes.
"Losing another ship now is bad timing. It may raise concern over America's defensive capabilities and it could send the wrong signal to North Korea and China," a senior Japanese Maritime Self Defence Force officer said, asking not to be identified because he is not authorized to talk to the media.
An international search-and-rescue operation involving aircraft, divers and vessels from the United States, Singapore, Malaysia, Indonesia, and Australia is looking for the 10 U.S. sailors missing since Monday's collision.
On Tuesday, U.S. Navy and Marine Divers found human remains inside sealed sections of the damaged hull of the USS John S McCain, which is moored at Singapore's Changi Naval Base. The Navy has not yet announced the identities of the bodies discovered. U.S. Navy is also working to identify a body found by the Malaysian navy about eight nautical miles northwest of the collision site. Photos posted on the Twitter account of a Malaysian navy frigate on Wednesday showed crew carrying what appeared to be a body to a U.S. Navy helicopter.
The latest collision has already prompted a fleet-wide investigation and plans for temporary halts in U.S. Navy operations. John S. McCain's sister ship, the USS Fitzgerald, almost sank off the coast of Japan after colliding with a Philippine container ship on June 17. The bodies of seven U.S. sailors were found in a flooded berthing area after that collision.
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http://tmsnrt.rs/2ijfj9l
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