Prices of de-fleeted cars at auction fell in July, as the age and mileage of vehicles rose slightly, according to Manheim's latest monthly barometer of activity.

Despite falling by an average of £377 (5.1%) compared to wholesale prices achieved in June, the value of ex-lease and contract hire cars is still £371 higher (5.6%) now than in July 2012.

The latest figures from the Manheim Market Analysis shows that the decrease in value in July can be put down to an increase in both the average age and mileage of the de-fleeted vehicles appearing at the auctions.

Clearly with the average age jumping by two months and the average mileage increasing by 710, to 50 months and 58,078 miles respectively, the prices achieved in the wholesale market were affected.

Daren Wiseman, valuation services manager at Manheim Auctions, said: "It's significant to note that auction prices in July reacted to an increase in age and mileage of vehicles, by falling back from £7,368 to £6,991.

"This shows that although there is generally still a shortage of wholesale stock coming to auction, the market is perhaps more focused on selling than buying at the moment."

Looking at the figures in more detail, the average selling price of de-fleet vehicles fell for nine of the ten segments from June to July, most notably for executive models, which fell by £1,053.

This is reflective of an increase in average age by three months and 5,481 in mileage.

In contrast, the one increase in average values was seen in the large family models, which rose by £152 from last month.

Year-on-year, six of the 10 segments saw an increase in value, most markedly for the executive sector, which, despite the July blip, has seen values rise by £842 throughout the year.

Wiseman concluded: "Although the market for de-fleet vehicles is facing the inevitable effects of the summer, things have not been as gloomy as first thought.

"It will be interesting to see how the latter portion of 2013 compares with the first seven months, as 2013 has so far been fairly positive for fleet managers looking to dispose of stock, with the percentage of new price retained remaining consistent throughout the year so far."