The slowdown in sales of new motorcoaches during the second quarter became a full-fledged backslide during this year's third quarter, new figures released by National Bus Trader magazine show.

A total of 457 new coaches were sold during July, August and September, the smallest quarterly total since the third quarter of 2005 when 428 were purchased, and 15 percent below the third quarter a last year when 538 were delivered.

The third quarter is typically the slowest sales period of the year for new over-the-road buses in North America, but this year the normal quarterly dip became a double-digit decline.

The drop is being blamed primarily on a significant number of tour and charter bus operators balking at buying '07-model coaches that have higher price tags because they're equipped with reduced-emission 07 engines and other new features. In other words, sticker shock and an understandable reluctance to be one of the first kids on the block with one of the updated engines.

The third-quarter slide followed 11 consecutive, year-over-year quarterly increases that began in the final quarter of 2004. The sales funk that ended in '04 had begun in 1999.

Larry Plachno, editor of National Bus Trader, said the third-quarter sales decrease was pretty much across the board, involving virtually all models built for private-sector tour-and-charter bus operators.

Sales by brand dropped from 10.5 to 28.6 percent. Those coach builders with the smallest percentage declines apparently were the companies who still had a stash of '06 engines they could mount in '07 coaches.

One manufacturer reportedly has taken orders for '08 coaches equipped with '06 engines, indicating the coach maker had squirreled away a significant inventory of the cheaper, less-sophisticated engines.

The top three selling new-coach models the MCI D4500, J4500 and Van Hool C2045 captured more than 60 percent of the market in the third quarter. That compares to 54.2 percent for the three models in the second quarter, 57.3 percent in the first quarter and 55.7 percent for the fourth quarter of last year.

That means third-quarter buyers focused their purchases on more bread-and-butter coach models.

Also, for the first time since the initial quarter of 2004, the top selling model was not the MCI J4500.

The other four top sellers during the third quarter were the Prevost H3-45, the Setra S 417, the MCI D4505 and the Van Hool T2145. The T2145 replaced the Prevost X3-45 among the top seven sellers.

Other highlights from the third quarter:

Purchases by Canadian coach operators slowed noticeably. Canadian sales accounted for only 5.5 percent of the total in the third quarter, compared to 14.6 percent in the first quarter and 12.9 percent in the second quarter of this year.

Sales of conversion shells remained strong in the third quarter, with 14 percent of the market, up from third-quarter '06 sales of 11.9 percent. Conversion shells took 13.3 percent of the total in the second quarter of this year and 14.4 percent in the first quarter.

Particularly hurt by the third-quarter decline in purchases by tour and charter operators was ZF, maker of the AS-Tronic auto-stick shift transmission. Since AS-Tronics are not normally used in public-sector coaches or conversion shells, the percentage of new coaches delivered in the third quarter with ZF transmissions dropped to 25.4 percent.

Still, more MCI J4500s, Van Hool C2045s and Prevost H3-45s were sold with ZF AS-Tronics than with Allison B500 transmissions.

It also is worth noting that Setra sold its first S 417 model equipped with a ZF AS-Tronic during the third quarter, thereby joining MCI, Prevost and Van Hool in delivering coaches with the transmission.