The move leaves unclear the destination of the black box, which may yield vital details of what caused the Boeing Co 737 MAX 8 to plunge to the ground, killing 157 people. A spokesman for Ethiopian Airlines had said earlier that the black boxes recovered from the crashed plane would be sent to Germany for analysis.
Meanwhile, Canada became the latest country to ground 737 MAX jets on Wednesday, saying satellite data suggested similarities to a previous crash involving the same plane model. Countries around the world - with the notable exception of the United States - have grounded the 737 MAX jets or banned them from flying over their airspace since the Ethiopian Airlines flight crashed soon after taking off from Addis Ababa on Sunday.
The still unexplained crash followed another involving a Boeing 737 MAX in Indonesia five months ago that killed 189 people. Although there is no proof of any link, the twin disasters have spooked passengers, led to the grounding of most of Boeing's 737 MAX fleet and hammered shares in the U.S. planemaker, the world's largest.
Canadian Transport Minister Marc Garneau told a news conference that Ottawa would stop 737 MAX 8 and 9 jets from leaving, arriving or flying over Canada. He said satellite data suggested similarities between the flight profiles of the Ethiopian jet and that of a Lion Air plane of the same type that crashed in Indonesia last year. Both planes crashed shortly after takeoff.
It is the first time since Sunday's crash that a regulator has taken a grounding decision after receiving new data, though there is still no data for now from inside the aircraft. Air Canada and rival WestJet Airlines operate a total of 37 Boeing 737 MAX jets.
Boeing has said it has full confidence in the 737 MAX - a model that has 371 jets in operation around the world. Ethiopian Airlines.spokesman Asrat Begashaw said it was still unclear what happened on Sunday, but its pilot had reported control issues - as opposed to external factors such as birds.
"The pilot reported flight control problems and requested to turn back. In fact he was allowed to turn back," he said. PAYING RESPECTS AT THE SITE
At the rural site where Flight ET 302, which was bound for the Kenyan capital Nairobi, came down near the village of Gora-Bokka, dozens of grief-stricken relatives paid their respects. Only charred fragments of victims remain, meaning it will take weeks to identify all of them using dental or DNA testing.
The passengers came from more than 30 nations. One elderly couple collapsed into each other's arms after strewing flowers in front of a picture of a smiling young woman, while a family propped each other up, tears coursing down their faces. Another shrine showed images of a young couple embracing.
Since the Indonesia crash, there has been a focus on an automated anti-stall system in the 737 MAX that dips the aircraft's nose down. Many airlines were keeping to schedule by using other jets while economic woes meant some may be grateful for a pause. The biggest impact could be on future deliveries given Boeing has nearly 5,000 more 737 MAXs on order.
India said it would not take any deliveries until safety concerns were cleared and Ethiopian Airlines said it would decide whether to cancel orders after a preliminary probe. Passengers were fretting too, with many seeking reassurances they would not be flying on a 737 MAX. Kayak.com was the first big site to say it would modify filters to allow customers to exclude particular types of planes from queries.
Boeing shares have fallen about 11 percent since the crash, losing some $26 billion of market value. They were 0.7 percent higher in New York around midday on Wednesday. BOEING'S APPEAL TO TRUMP
The pilots' union for Southwest Airlines, which has the largest 737 MAX fleet in the world with 34 aircraft, said on Wednesday that it remained confident in the model even after Canada's decision to ground the jet. The U.S. Federal Aviation Administration's (FAA) acting administrator Dan Elwel said its review of the model had shown "no systemic performance issues".
U.S. President Donald Trump, an aviation enthusiast whose ties with Boeing run deep, received safety assurances personally from its Chief Executive Dennis Muilenburg. Democratic Senator Richard Blumenthal suggested on Twitter that an upcoming hearing on the crash would focus on that conversation. "Chief Exec's personal plea to Trump leaves more questions than answers," he said.
Norwegian Air said it would seek recompense for lost revenue and extra costs after grounding its 737 MAX aircraft. The new variant of the world's most-sold modern passenger aircraft was viewed as the likely workhorse for airlines for decades. But October's Lion Air crash in Indonesia sparked a debate on automation, particularly over a software system designed to push the plane down to stop a stall during flight.
The United Arab Emirates' aviation regulator said on Tuesday there were "marked similarities" between the crashes, and China's regulator noted both occurred shortly after take-off. In November, two incidents were reported to the NASA-run Aviation Safety Reporting Database that involved problems in controlling the 737 MAX at low altitude just after take-off with autopilot engaged, according to documents first published by the Dallas Morning News and verified by Reuters.
"We discussed the departure at length and I reviewed in my mind our automation setup and flight profile but can't think of any reason the aircraft would pitch nose down so aggressively," one pilot said. (Additional reporting by Duncan Miriri and Aaron Maasho in Addis Ababa; Kumerra Gemechu in Gora-Bokka, Ethiopia Omar Mohammed and Maggie Fick in Nairobi; Tim Hepher in Paris; Chris Sanders in Washington; Jamie Freed in Singapore; Terje Solsvik in Oslo; Aditi Shah in Mumbai; Sanjana Shivdas in Bengaluru; Aleksandar Vasovic in Belgrade; David Ljunggren and Julie Gordon in Ottawa Writing by Andrew Cawthorne, Frances Kerry and Bill Rigby Editing by Jon Boyle and Gareth Jones)