Incentives on new cars and trucks dipped slightly in November, but Detroit's Big Three vehicle manufacturers added to their deals in advance of an expected end-of-year sales push, Reuters reported.

The report said manufacturer incentives averaged $US2,685 per vehicle in November, a $30 decline 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 US economy, the news agency noted.

According to Reuters, Detroit motor industry executives said on Tuesday when they announced November sales results that they were hoping the healthy economy would let them reduce incentives some time next year. As for the past two years, the US Big Three led the market in November, with vehicles averaging $3,663 in deals, a $38 increase from October, the report added.

General Motors averaged $4,036 per vehicle, thanks to a boost on car incentives, Chrysler cut its average slightly, to $3,731 per vehicle, on lower truck incentives and Ford 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.

The report said Japan's Big Three were mostly able to cut back on incentives, thanks in part to more new models reaching the market. Toyota and Nissan cut their incentives by 10%, with Toyota offering $723 per vehicle in November and Nissan averaging $1,344. Honda raised its deals, but at $553 per vehicle still offered less than any other manufacturer, Reuters added.