Ocean Infinity will only receive payment if it's successful in finding the remains of the plane, which went missing in March 2014 en route from Kuala Lumpur to Beijing with 239 people on board.
The 90-day search will initially take place over an area of 25,000 square kilometers (just under 10,000 square miles) off Australia's west coast, to the northeast of the original search area.
The payment is on a sliding scale. If the debris field, cockpit voice recorder or flight recorder are discovered within the first 5,000 sq km (1930 sq mi) searched, Ocean Infinity will command a fee of $20 million, rising to $70 million if any of those items are found outside the initial 25,000 sq km area.
The agreement was signed by the Malaysian government and Ocean Infinity CEO Oliver Plunkett at a ceremony in Kuala Lumpur Wednesday, attended by the families of some of the missing passengers. Australia led the initial search, after analysis showed the plane was most likely to have sunk to the bottom of the ocean off the coast of West Australia.
Ocean Infinity, which specializes in the collection of "high resolution geophysical seabed data," said in a press release that its command vessel, Seabed Constructor, is en route and "close to" the search area.
In addition to the Ocean Infinity's 65 crew members, two personnel from the Royal Malaysian Navy will accompany the search as representatives, Malaysian Transport Minister Liow Tiong Lai said Wednesday.
All costs would be borne by the Malaysian government, Lai said, but the search must be successfully completed within 90 days for the company to claim its reward.
The original search, which covered 120,000 sq km (46,000 sq mi), cost roughly $150 million.
Lai said that he hoped the wreckage would be found "as soon as possible," to "bring some closure" to the families of those who perished.
In December 2016, an Australian government report confirmed
that teams searching for the missing aircraft had been very likely been looking in the wrong place. New analysis suggested the search area in which Ocean Infinity will focus.
The search will be undertaken by a fleet of eight autonomous underwater drones "packed with sensors," whose data from the seabed is then analyzed on board the surface vessel, Plunkett said.
The drones -- Autonomous Underwater Vehicles (AUVs) -- do not need to be towed by surface ships, as was the case with previous searches, which, according to Ocean Infinity, makes their search capabilities more effective.
"The ability to operate untethered independent missions allows the AUVs to go deeper and collect higher quality data, making this technology ideal for the search," the Ocean Infinity press release states.
Plunkett said Wednesday that discounting the already searched areas and employing Ocean Infinity's AUV technology gave him confidence the company would discover the wreckage of the plane where others have failed.
He said the drones could cover 1,200 sq km a day, enabling the team to search beyond the initial search area, should nothing be found there.
Plunkett added that since the first underwater drones were delivered in 2017, his team has logged 6,100 hours of AUV dive time in a variety of projects. The submersibles had reached a depth of 5,680m, he said.
The mystery of MH370 has gripped the world since its disappearance on March 8, 2014. The flight was carrying individuals and families from 14 different countries, though most of the passengers and crew were from China and Malaysia.
Some debris definitively linked to the plane has been found, but for the most part its whereabouts remain unknown.
Competing theories have surfaced as to what led to the plane's disappearance, though none are conclusive.
In its final report, released in October 2017, investigators for the Australian Transport Safety Bureau said it was "almost inconceivable" that authorities were no closer to knowing its ultimate fate.
The Australian government didn't rule out a future resumption of the search if "credible new information" came to light.