The report for December also found a 33.7 per cent decrease month-on-month in average daily browsers, from 319,005 in November to 211,537.
These figures relate to traffic in the same month that Metro launched its new responsive website.
Product development director at Metro Jamie Walters said: "Following the relaunch of our fully responsive mobile optimised Metro.co.uk, which saw us move our site to the WordPress VIP platform, we've seen a fluctuation in traffic as is normal with any redesign of this size.
"As anticipated, we’re already seeing an upturn in January both for UK and global traffic with our urbanite audience consuming more content on the move with page views up 33 per cent across mobile devices."
The results for Metro were the biggest decreases recorded by UK newspaper websites audited by ABC in December, but not the only ones.
The Evening Standard recorded a 2.4 per cent fall in monthly browsers, and a 8.5 per cent drop in average daily browsers. The Guardian website also saw a fall in both monthly browsers of 2.8 per cent and average daily browsers of 7.1 per cent.
The Telegraph also recorded a 1.7 per cent decrease in monthly browsers, and a 5.7 per cent fall in average daily browsers.
Meanwhile the Independent's website saw the biggest increase in both monthly browsers and average daily browsers, of 18.9 and 13.8 per cent respectively.
Mirror Group Digital had the second biggest increase of 11.9 per cent in monthly browsers and 7.8 per cent in average daily browsers.
The Mail Online saw an increase of 1.7 per cent in monthly browsers for December, but a slight drop of just under one per cent in average daily browsers.
Update: This article was updated to correct Jamie Walter's job title to product development director.