MERCEDES-Benz North America and BMW appear to be on collision course over whose car was the most successful luxury nameplate in the United States last year.

According to a leading auto website, worldcarfans.com last week, official manufacturer numbers had shown BMW sold 281,460 cars in 2012, while Mercedes-Benz sold 7,326 less units.

But the figures have been contradicted by Mercedes-Benz which quotes data gathered by Polk, the bible of the automotive industry.

"Polk mentions Mercedes-Benz posted 274,123 registrations, while BMW had 268,498. Those sales figures from early January are not entirely relevant since some companies like BMW book the sale after the car is shipped from the factory to the dealer. This probably means BMW delivered more cars to dealerships in December to climb on top," the website said.

It said that Mercedes-Benz North America chief Steve Cannon had accused BMW of using "various methods" to increase sales at the end of the year, adding that Mercedes-Benz had been leading BMW for 11 months.

Cannon who was speaking at the monthly meeting of the International Motor Press Association in New York City, reportedly said the difference between Mercedes-Benz sales and registrations was 11, while the discrepancy at BMW was 13,000 units.

Autodata, which also keeps figures for the industry, had put BMW in the top spot, before Polk compiled its registration data showing that Mercedes customers registering new vehicles topped the Bavarian automaker -- 274,123 registrations compared with 268,498 -- in the most recent calendar year.

Worldcarfans.com said that in terms of sales posted, BMW had bested Benz 281,460 to 274,134. But sales are recorded somewhat inconsistently from automaker to automaker.

"Some book the sales as soon as they are shipped from factory to dealer. There is perennial gamesmanship between the two German rivals, and the sales numbers suggest that BMW pushed out some extra sheet metal to dealers in the last four weeks of the year."

Autoblog quoted Cannon as saying: "Cars sold to people in the calendar year who then register their vehicles seems to be a more accurate measure of real sales than just the raw sales numbers."

A BMW spokesman said the company stood by its sales figures, the website said.