Automakers spent $2.3 billion in October on incentives designed to stimulate sales in the United States, according to a report from Edmunds.com.

The report estimates the average automaker manufacture incentive in the U.S. was $2,648 per vehicle sold in October 2008, down $253, or 8.7 percent, from September 2008, and up $471, or 21.6 percent, from October 2007.

The total amount spend in October represents a 17.4 percent decrease from September.

"Automakers have to do what they can to stimulate sales while still being fiscally responsible during these shaky economic times," said Jesse Toprak, executive director of industry analysis for Edmunds.com. "The industry is still far below the record average incentive of $3,146, which was reached in September 2004."

According to the report, combined incentives spending for domestic manufacturers averaged $3,718 per vehicle sold in October 2008, down from $4,041 in September 2008.

From September 2008 to October 2008, European automakers increased incentives spending by $93 to $2,866 per vehicle sold; Japanese automakers increased incentives spending by $107 to $1,495 per vehicle sold; and Korean automakers increased incentives spending by $101 to $2,417 per vehicle sold.

Ford was the only member of the Big Three automakers to raise their incentive spending per vehicle from September to October, going from $3,639 to $3,758. That's up from $3,205 per vehicle spent at this time last year.

Chrysler spent $3,598 in October, down from $4,679 in September, and General Motors spent $3,716, down from $3,957.

Both Toyota and Honda have significantly increased their per-vehicle incentives since last year, going from $706 in October 2007 to $1,632 last month for Toyota and from $639 to $1,082 for Honda.

"Toyota is on track to achieve record market share with record incentive levels, and Honda isn't far behind," said Edmunds' AutoObserver.com Senior Editor Michelle Krebs. "Their incentives programs are getting more aggressive and are catching consumers' eye because they are unusually good deals for those brands. The automakers that tend to offer repetitive incentives will need to do something creative to have their message be heard."

Comparing all brands, in October MINI spent the least at $36 followed by Scion at $155 per vehicle sold. At the other end of the spectrum, HUMMER spent the most, $5,587, followed by GMC at $4,889 per vehicle sold. Relative to their vehicle prices, Mercury and HUMMER spent the most, 16.5 percent and 14.6 percent of sticker price, respectively; while MINI spent just 0.2 and Scion spent 0.9 percent.