Volkswagen AG's sales in Japan skidded 9.1 percent from a year earlier to 5,989 vehicles in September, sources familiar with the imported vehicle industry said Monday. The shortfall reflected fallout from VW's emissions manipulation scandal.

By brand, VW came second by a wide margin to Daimler AG's Mercedes-Benz luxury vehicle division, which sold 8,032 vehicles. It increased the likelihood that VW will yield to Mercedes-Benz the lead it has held for the past 15 years.

VW's loss stood out in the month as other major brands either registered sales increases or slight declines, the sources said.

Cumulative sales from January to September fell 11.7 percent to 44,193 units at VW, while the figure for Mercedes-Benz reached 49,666, up 13.2 percent.

Sales by VW's Audi unit increased by 1.3 percent to 3,628 units in September.

In the United States, where VW was revealed to be using special software to cheat on emission tests for diesel engines, the German automaker managed to eke out a 0.6 percent increase in September sales. Other major carmakers, such as General Motors Corp. and Toyota Motor Corp., all posted double-digit gains.