The weekly lads' mag lost 11,416 copy sales in the last six months of 2010 and is 33,433 copies and 32.8% down from the same period in 2009.
Bauer has moved decisively to address the ailing sales by detailing its plans for a drastic overhaul of the title in a bid to differentiate the magazine from IPC Media's rival Nuts. It also intends to prevent readers from feeling "too embarrassed" to read the title in public.
In an email to media planners and buyers, seen by Media Week, Geoff Campbell, Zoo's managing director, addresses the magazine's new direction.
Bauer Consumer Media is set to present the new strategy and product to agencies on Monday (21 February).
Campbell said: "Over recent weeks, editor of weekly lads' mag Zoo, Damien McSorley, has been hard at work with his team redeveloping the magazine to re-energise the brand among its audience of fun-loving young men.
"We're more determined than ever to keep improving each and every week to make Zoo the ultimate weekly lads' mag."
Addressing the subject of naked women, Campbell set out the magazine's vision. He said: "For too long, the lads' mags have chased each other in circles, focusing almost exclusively on who could offer the biggest and rudest spreads of topless glamour girls. We have deliberately stepped away from that particular spiral.
"Yes, Zoo celebrates gorgeous girls. But they're famous, unexpected, glamorous and sexy, not sleazy, so readers won't be embarrassed to read Zoo on the way to work or in front of their girlfriends."
The reshaped magazine will include a new entertainment section and sports and gadgets guides.
Vanessa Clifford, head of press at Mindshare, said: "Bauer are talking about turning Zoo into the ultimate weekly lads' mag. I'm not sure the world wants or needs lads' mags anymore, and that's nothing to do with the content, it's just the attitude of them. The era of lads' mags is departing."
Zoo's rival IPC Media's Nuts also suffered a period-on-period drop in yesterday's ABCs, however, it was not as severe.
The magazine fell a relatively small 3.3% in the last six months of 2010 from 147,134 copies to 142,212 copies. Its fall from the last six months of 2009 was more severe, at 19.6%.