
Revenue at the MoS fell nearly 40%, from £23.1m to £14.4m year on year for the period January to June 2009, the biggest drop of any national paper, according to unofficial Nielsen data, which excludes supplements.
The figures also show the volume of column centimetres sold had dropped more than 33%, suggesting the paper had not lowered its rates.
Alan Brydon, head of press and outdoor at MPG, confirmed the new regime at DMGT had had an effect. "The Mail on Sunday this time last year was sold by its old sales team.
"Now it has a new sales team (merged under MD Guy Zitter), it has hardened its rate."
While a number of media agencies told Media Week it is the first time Rothermere had been to meet them, Zitter, managing director of Mail Newspapers, denied he was worried about the Sunday market.
He said: "His primary focus has been on digital and he has come back with a couple of ideas from these meetings. There is no panic and it is good for him to visit people lower down the food chain."
While DMGT this week reported a slowdown in the rate of decline in ad revenue across its newspaper operations, the data shows, for the most part, Sunday papers are struggling, due in part to retail clients preferring daily titles.
The Independent on Sunday was the second worst performer of the Sundays, down 26.15% to £2.43m, according to the data. Revenue at its sister title fell 30.09% to £8.03m.
"The qualities are having a tougher time than the red tops," said Paul Thomas, investment director at Mindshare. "Corporate advertising is dying away, as is financial advertising. The qualities don't get the likes of Argos and Lidl advertising."
Accordingly, revenue at The Sun was buoyed by retail advertisers. The paper fell just 4.97% to £74.3m, making it the least hard hit of the dailies.