Although the overall supply of used units is still restricted — largely due to sluggish new-car sales from the recessionary years — it seems that a flood of end-of-term fleet vehicles has led to some alleviation in wholesale pricing lately, according to ADESA’s Tom Kontos.

In fact, the average wholesale price in September was $9,750, a 0.9-percent year-over-year decrease and a 1.3-percent sequential dip, ADESA Analytical Services data indicates.

“As we anticipated, fall de-fleeting appears to be putting downward pressure on wholesale used vehicle values by easing some of the supply tightness that has propped up prices for more than two years,” said Kontos.

At the end of last year, ADESA pointed out that sales into rental fleets in 2010 climbed by 283,644 units compared to 2009, meaning fall 2011 would likely see a significant uptick in end-of-service rental units coming into the used market.

“This expectation appears to be materializing and causing wholesale prices to fall at slightly more than their typical seasonal rates,” he explained. “Nevertheless, supply continues to be relatively tight, primarily reflecting lost new-vehicle sales volumes during the recession of 2008-2009 — vehicles which would otherwise be reaching a prime age for re-entry into the market as used units.”

Breaking September’s data down by segment, car prices rose 4.4 percent year-over-year, but fell 3.2 percent from August. Meanwhile, truck prices dipped 5.7 percent from September 2010, but climbed 0.5 percent month-over-month.

Kontos pointed to gas price alleviation, which has led to the car-price declines and allowed truck prices to modestly bounce back from the fuel-price hikes earlier in 2011. As fuel costs rose, they pushed truck prices down.

By seller type, prices in manufacturer sales were up 3.4 percent year-over-year and down 3 percent from August. For fleet/lease units, prices fell 1.9 percent from August and 0.8 percent from September 2010.

Dealer consignment prices were down 4 percent month-over-month and up 5.5 percent year-over-year.

Looking at auction inventory levels, these came in at an estimated 31 days’ supply at the end of September, up from 26 days at the end of the previous month, according to ADESA Analytical Services. From May through July, auction inventory was at a record low of 24 days.

“September marks the first month in over two years that days-supply of auction inventories matched year-ago levels; auction industry inventories have been below year-ago levels since July 2009, by our estimates,” Kontos explained.

“The rise in inventory levels is primarily a reflection of higher fall de-fleeting,” he added.