Ofcom's annual News Consumption study indicates 41% of the population use the net to keep up-to-date with current affairs, while 40% read a paper.
But it suggests that TV remains the most popular source.
It said 75% accessed news this way.
While the net cannot yet claim the top spot, the study did suggest it was the fastest-growing medium.
Radio was the only other area that had an increase over the past year.
Ofcom suggested 36% of people in the UK tuned in to radio news, a modest rise from 35% in 2013. By contrast, the net leapt ahead from 32% to today's 41% figure.
Younger people
The figure for newspapers was unchanged over the period.
The watchdog said it believed that younger people were largely responsible for the surge in net use, with 60% of the 16-to-24 age group telling it they used Facebook, Whatsapp, Twitter and other sources to keep abreast of developments.
This may be in part because they spend more time on mobile devices than their older counterparts.
Ofcom noted its study indicated that 40% of younger people used a mobile phone for news and 15% used a tablet. The comparable statistics for the over-55s were 15% using phones and 7% tablets.
The organisation said that it surveyed 2,731 UK adults to form its conclusions.
One expert suggested the numbers needed to be viewed in this light.
"You have to be careful with surveys as what people say they do and what they actually do doesn't always match," said Ian Maude, of the consultants Enders Analysis.
"Right now there isn't any solid data on how much time is spent using mobile apps, though it should be available later this year.
"Even so, we can be sure that younger people increasingly get their news online, though it's not clear if or when the web and apps will overtake TV."
Mainstream brands
The report is the latest of its kind to highlight the challenge facing traditional media.
Recent figures by the National Readership Survey suggest the Sun newspaper, for example, shed one million readers over the past year, taking its current tally to about six million. The Sun's decision to put its online version behind a paywall has also caused its net readership to fall, bucking the wider trend.
Another study, published this month, by the Reuters Institute for the Study of Journalism indicated that just 7% of those polled in the UK said they had paid for news in the past year.
However, it added that "mainstream" news brands still had huge appeal online for the audience, with the Daily Mail, BBC, Sky News, Guardian, Telegraph and the "local newspaper" category all appearing in their top 10 list of most used internet-based sources.
Source: BBC News
