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SYDNEY Aug 6 (Reuters) - Dutch oil industry services firm Fugro is to lead Australia's search of the Indian Ocean seafloor where missing Malaysia Airlines flight MH370 is believed to lie, hoping to solve the mystery of its disappearance five months ago.
Australia on Wednesday awarded Fugro the lead commercial contract to use its deepsea survey vessels for the search, after months of hunting by up to two dozen countries revealed no trace of the missing Boeing 777 airliner.
The aicraft carrying 239 passengers and crew, disappeared on March 8 shortly after taking off from Kuala Lumpur bound for Beijing.
Investigators say what little evidence they have to work with suggests the aircraft was deliberately diverted by thousands of kilometres from its route before eventually crashing into the Indian Ocean off the coast of Western Australia.
The next phase of the search is expected to start within a month and take up to a year, focusing on a 60,000 sq km (23,000 square miles) patch of ocean some 1,600 km (1,000 miles) west of Perth.
Australian Transport Minister and Deputy Prime Minister Warren Truss said Fugro was selected after "offering the best value-for-money technical solution" for the seafloor search.
"I remain cautiously optimistic that we will locate the missing aircraft within the priority search area," he told reporters in Canberra.
Fugro will use two vessels equipped with towed deep water vehicles carrying side scan sonar, multi beam echo sounders and video cameras to scour the seafloor, which is close to 5,000 m (16,400 ft) deep in places.
The Dutch company is already conducting a detailed underwater mapping of the search area, along with a Chinese naval vessel.
"We haven't completed the mapping, so we are still discovering detailed features that we had no knowledge of, underwater volcanoes and various other things," said Martin Dolan, the head of the Australian Transport Safety Board, which is heading the search.
"We are finding some surprises as we go through."
The company, which usually conducts surveys for oil and telecommunication companies, admitted the water depth, remoteness of the survey area as well as the rough seafloor topography bring challenges for the operation.
"We're putting the map together as we go and we find that certain areas are very rugged topography for sure," said strategy director Rob Luijnenburg.
"We always want to do our best for customers... but because of the importance and sensitivity of this project, this is really one that we wanna do right."
Malaysia will provide four vessels and gear to aid seafloor mapping and the search of the storm-lashed and isolated area.
Minister Truss said he would talk to his Malaysian counterpart later this month about sharing search costs. Australia has set aside up to A$90 million ($84 million) and estimates a 12-month search of the area will cost around A$52 million.
The search is already the most expensive of its type ever undertaken.
China, which had 153 nationals on board MH370, has been heavily involved, providing ships, aircraft and satellite technology. One Chinese vessel will stay in the search area until mid-September, but Truss said China had shown no sign that it would cover any of the commercial search costs.
Dozens of ships and planes scoured vast areas of ocean in the months after the plane disappeared but found only rubbish.
The search was narrowed in April after a series of acoustic pings thought to be from the plane's black box recorders were heard near its last location shown by satellite data analysis.
But officials now say wreckage from the aircraft was not in the area they had identified, requiring the search to be expanded and moved further to the southwest.
Malaysia Airlines has been hit this year by the loss of two of its airliners, after Flight MH17 was shot down over a conflict zone in eastern Ukraine. (1 US dollar=1.0749 Australian dollars) (Additional reporting by Matt Siegel in Sydney and Jussi Rosendahl in Amsterdam; Editing by Clarence Fernandez and Greg Mahlich)