SANTA MONICA, Calif. — The average automaker incentive was largely unchanged in March compared with February, but incentives generally are likely to rise for the next several months as automakers try to break the sales slump, Edmunds.com predicts.

"Incentives are likely to rise through the spring and summer," said Jesse Toprak, executive director of Industry Analysis for Edmunds.com. “We anticipate that this will be especially true for the European automakers, as long as the euro remains strong.”

Edmunds.com estimates the average automotive manufacturer incentive in the U.S. was $2,519 per vehicle sold in March, essentially unchanged from February but up $94, or 3.9 percent, from March 2007.

Edmunds.com estimates the combined incentives spending for domestic manufacturers averaged $3,424 per vehicle sold in March, up from $3,384 in February. From February to March, European automakers increased incentives spending by $236 to $3,067 per vehicle sold; Japanese automakers decreased incentives spending by $73 to $1,295 per vehicle sold; and Korean automakers increased incentives spending by $352 to $2,126 per vehicle sold.

In March the industry's aggregate incentive spending is estimated to have totaled approximately $3.34 billion, up 13.6 percent from February 2008. Chrysler, Ford and General Motors spent an aggregate of $2.3 billion, or 67.7 percent of the total; Japanese manufacturers spent $658 million, or 19.7 percent; European manufacturers spent $290 million, or 8.7 percent; and Korean manufacturers spent $130 million, or 3.9 percent.

Among vehicle segments, large trucks had the highest average incentives, $4,368 per vehicle sold, followed by large SUVs at $4,094. Compact cars had the lowest average incentives per vehicle sold, $1,023, followed by sport cars at $1,574.

Analysis of incentives expenditures as a percentage of average sticker price for each segment shows large trucks averaged the highest, 13.6 percent, followed by large cars at 13.1 percent of sticker price. Sports cars averaged the lowest, 5.3 percent, followed by luxury sport cars at 5.7 percent of sticker price.

Comparing all brands, trends from the past year continued: BMW's Mini spent the least — virtually nothing — followed by Scion at $131 per vehicle sold. At the other end of the spectrum, Cadillac spent the most, $5,532, followed by Saab at $5,501 per vehicle sold. Relative to their vehicle prices, Dodge spent the most, 16.7 percent and Saab followed in at 15.3; Mini spent virtually nothing and Scion spent just 0.8 percent.

True Cost of Incentives for the "Big Six" Automakers

Automaker—March 2008—February 2008—March 2007

Chrysler Group—$4,142—$3,520—$4,237

Ford—$3,017—$3,317—$3,114

General Motors—$3,271—$3,328—$2,832

Honda—$1,297—$1,209—$1,157

Nissan—$2,031—$2,159—$2,043

Toyota— $898—$1,044—$714