Meng is wanted on suspicion of defrauding banks to get around US sanctions on Iran.
Her arrest infuriated China, which called it a human rights violation and vowed serious repercussions if Meng were not released. In the weeks since, Chinese authorities have seized two Canadians on national security charges, although they have denied that the detentions were politically motivated.
Schellenberg's initial arrest in 2014 and subsequent trial in 2016 were tracked by Canadian officials but did not attract any media coverage.
In an unusual move last week, China's government issued invitations to several foreign news organisations to cover the trial in Dalian, prompting speculation that Beijing was seeking to use Schellenberg's case to exert pressure on Ottawa.
Donald Clarke, a specialist in Chinese law at George Washington University, said retrials were ordered in, at most, 2 per cent of Chinese criminal cases - and foreign media are typically not invited to observe them.
It is possible that "China wished to show Canada that it is deadly - literally deadly - serious about getting Meng Wanzhou released before she is extradited to the United States," Clarke said in an email. "If this hypothesis is correct, then China has moved from merely detaining Canadians as hostages to actually threatening to kill a Canadian (who otherwise would not have been executed.)"
Richard Walker, a spokesman for Global Affairs Canada, the department of the Canadian Government in charge of diplomatic and consular relations, said Canadian officials have been following the case for "several years" and have been providing consular assistance. He declined to provide more information about the case, citing privacy laws.
According to a statement issued by the court, prosecutors found new evidence that Schellenberg was part of an international smuggling ring and believed that his previous "light punishment was obviously not appropriate".
The court statement said the open trial showed that Schellenberg enjoyed full legal rights - including the right to a translator - and was attended by Canadian Embassy representatives as well as Chinese and foreign media.
The Wall Street Journal, which attended the hearing, reported instances of mistaken or omitted translations during the proceeding.
Judges deliberated for 20 minutes after the three-hour hearing - which was taken up mostly by a lengthy defense from Schellenberg's attorney, the Journal reported.