BEIJING -- Chinese postal authorities said the permits of 116 express delivery companies were canceled in 2012 and urged greater supervision amid a series of reports on problems with the booming sector.

"Some media have reported losses of mail, barbaric sorting and disparate clauses among some express delivery companies," according to a statement dated Monday on the website of the State Post Bureau.

More investigation should be carried out in response to the media reports and consumers' complaints, and local postal branches should further supervise the sector in order to improve service quality, the statement said.

As online shopping continues to boom, China's express delivery industry is expected to witness galloping growth over the next few years.

Deliveries will rise 21 percent annually, with revenues expected to grow 20 percent on average, according to the 12th five-year plan (2011-2015) for the express delivery industry released by the State Post Bureau.