A private US company will start a new search for the remains of Malaysia Airlines Flight MH370, whose disappearance in 2014 remains one of aviation's biggest mysteries.

The high-stakes deal, struck on Wednesday between Houston-based survey company Ocean Infinity and the Malaysian government, could yield a finder's fee of up to $70 million, or zero if it comes up empty.

The search, which is expected to last for 90 days, will focus initially on a 9,700-square-mile zone in the northern Indian Ocean identified by the Australian Transport Safety Bureau.

At a signing ceremony in Putrajaya, Malaysia, on Wednesday, Malaysian transport minister Liow Tiong Lai said, "There's an 85 percent probability of finding the wreckage at this new area."

Ocean Infinity CEO Oliver Plunkett said in a statement, "Whilst there can be no guarantees of locating the aircraft, we believe our system of multiple autonomous vehicles working simultaneously is well suited to the task at hand."

On March 8, 2014, flight MH370 carrying 239 people — two thirds of whom were Chinese — en route from Kuala Lumpur, Malaysia, to Beijing disappeared from radar screens while over the South China Sea.

Investigators said the plane continued to fly for several hours, turning back over Malaysia and then over the Indian Ocean. Theories to explain the plane's disappearance include the possibility that it ran out of fuel or the pilot deliberately crashed.

In what's become the most expensive search in aviation history, 26 countries have contributed planes, ships, submarines and satellite time to the effort, according to Reuters.

Previous search efforts, which were focused in the southern Indian Ocean, began in March of 2014, lasted more than three years and cost of more than $150 million.

Last January, Australian officials indefinitely suspended the search after scouring more than 46,000 square miles of ocean. They concluded in December that they may have been looking too far south.

In August, Australian and international investigators identified the new search area based on wind and ocean currents and satellite images showing 12 objects which could be aircraft debris floating in the ocean.

Ocean Infinity says it can deploy a fleet of up to eight unmanned submersibles — autonomous underwater vehicles (AUV) — from its vessel Seabed Constructor, which the company said is close to the area, enabling "work to commence imminently".

The AUVs can operate in water depths of 16 feet to nearly four miles and scan about 460 square miles per day.

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