Cash rebates, no-interest loans and other incentives on new cars and trucks dipped slightly in November, but Detroit's Big Three added to their deals in advance of an expected year-end sales push, according to a Reuters report.

Automaker incentives averaged $2,685 per vehicle in November, a $30 drop from October, according to industry analyst firm Autodata. Despite the decrease, industry sales strengthened in November to a seasonally adjusted annual rate of 16.8 million, thanks in part to an improving U.S. economy, Reuters said.

Detroit auto executives said Dec. 2, when they announced November sales results, that they were hoping the revitalized economy would let them ease up on incentives sometime next year. But as they have for the past two years, the Big Three led the market in November, with vehicles averaging $3,663 in deals, a $38 increase from October, according to Reuters.

General Motors Corp. averaged $4,036 per vehicle, thanks to a boost on car incentives. The Chrysler Group of DaimlerChrysler cut its average slightly, to $3,731 per vehicle, on lower truck incentives. Ford Motor Co. averaged $3,056 per vehicle, $2 more than October, as a $125 cut in its truck deals offset a $322 increase in car offers, Reuters said.

Japan's Big Three were mostly able to cut back on incentives, thanks in part to more new models hitting the market. Toyota Motor Corp. and Nissan Motor Co. Ltd. cut their incentives by 10 percent, with Toyota offering $723 per vehicle in November and Nissan averaging $1,344. Honda Motor Co. Ltd. raised its deals but at $553 per vehicle still offered less than any other automaker, according to Reuters.