Postmedia Network Inc. has the highest readership of all Canadian newspaper groups, with 10.7 million weekly print and digital readers, according to a new study by Vividata.

In Winnipeg, readership of the Sun, a Postmedia newspaper, showed a strong surge of 12.1%, averaging 111,000 readers a day, Monday to Friday, according to Vividata. During the same one-year period ending March 31, 2016, readership of the rival Free Press fell by 3.1%.

That trend also held for weekly readership, which showed an increase of 5.5% for the Sun and a dip of 3.5% for the Free Press.

Postmedia publishes the National Post, as well as daily broadsheets including the Calgary Herald, the Vancouver Sun, the Montreal Gazette and the Ottawa Citizen. Last year, it substantially increased its audience when it acquired 175 publications, including the Sun Media chain of tabloids, from Quebecor Media Inc. for $316 million.

By comparison, Torstar Corp. has 8.7 million weekly print and digital readers across Canada. In addition to the Toronto Star, Torstar publishes the Hamilton Spectator, the Waterloo Region Record and the free commuter paper Metro in Toronto, Vancouver, Ottawa, Calgary, Edmonton, Winnipeg and Halifax.

The Globe and Mail reaches 6.4 million weekly print and digital readers, according to the study. The Globe is fully owned by The Woodbridge Company Ltd., which also has a controlling stake in Thomson Reuters.

According to numbers released by Vividata in May, more than half of newspaper readership in Canada accesses content on multiple platforms, and cross-platform readership of digital content in Canada has grown more than four times since 2012.

"The dominant footprint of Postmedia across the country reinforces our commitment to providing quality content and audiences to our readers and clients in print and digitally. The combination of a wonderfully curated National Post section and strong local reporting is serving our customers very well," said Gerry Nott, Senior Vice President of Content at Postmedia.

The latest survey, released Tuesday, also shone a light on the reading habits of millennials. On the average week, daily newspapers reach 77% of millennials (18-34 year olds) and 85% of adults 50-plus. Digital and cross platform readership is strongest among millennials, at 38%, 18% higher than for adults 50-plus.

To that end, the combined Postmedia network draws the largest number of weekly digital readers at 6.1 million, while Torstar brings in 4.3 million. The Globe and Mail has digital readership of 4.5 million.

Adults over 50 remain the largest readership group for print newspapers, and Postmedia has a combined 8.1 million weekly print readers. TorStar brings in 7 million, and the Globe and Mail 3.6 million.

Vividata's survey was created in October 2014, after the amalgamation of media analysis firms NADbank and the Print Measurement Bureau. It replaces separate newspaper and magazine surveys that were conducted by the previous companies. Vividata measures audience performance for more than 70 daily newspapers, with 36,000 Canadians in over 50 markets surveyed.