En route to its sixth consecutive monthly sales gain, year over year, General Motors Co. says its average per-vehicle incentive fell below the industry average for the first time ever.

Citing data from J.D. Power and Associates, the auto maker says it had just $2,800 on the hood of each vehicle it sold in March – down some $2,000 from like-2009. The industry average for last month was $2,906, according to J.D. Power.

Historically, GM’s incentive spend has been the highest of any auto maker. “We no longer have that dubious honor,” says Susan Docherty, vice president-marketing.

Referring to the practice of inflating sales with aggressive incentive spending, Docherty tells journalists and analysts today during a conference call: “We’ve been down that road before and we know it’s a dead end.”

However, incentive-tracker Edmunds still has GM in the doghouse with an average of $3,519 on the hood of every vehicle – nearly $200 more than the $3,359 attributed to second-place Chrysler Group LLC and well ahead of the $2,742 industry average.

Not counting hybrids, GM’s March sales numbered 188,167 vehicles, 16.4% higher than like-2009, according to Ward’s data.

Light-truck deliveries comprised 60.7% of the total, as car sales skewed lower against the weight of 11 lost nameplates linked to the demise of Pontiac and Saturn. GM jettisoned the brands last year as part of its Chapter 11 filing.

But Brian Sweeney, U.S. sales and service vice president-Buick/GMC, says a direct-mail campaign aimed at retaining the estimated 1.6 million Pontiac and Saturn customers is gaining traction.

“We’ve had great response,” Sweeney says, adding free oil-change offers have attracted 110,000 displaced GM customers to Buick, GMC, Chevrolet and Cadillac dealerships.

And the drive is continuing.

March highlights include sales of the newly launched Buick LaCrosse. Deliveries of the redesigned fullsize sedan soared 223.4% above year-ago to 6,054.

And 35% of those buyers were new to GM, Docherty says, adding the average transaction price – company-wide – is on the rise, along with residual rates.

Boosted by lower incentives and a richer mix, GM’s average transaction price hit $31,300 last month, a $4,200 jump from like-2009, spokesman Tom Henderson tells Ward’s.

Meanwhile, Docherty says Automotive Lease Guide has informed GM it is raising by 1-2 points the residual rate tied to the auto maker’s midsize cross/utility vehicles.

Last month’s deliveries of the Buick Enclave, GMC Acadia and Chevrolet Traverse rose 36.1%, 31.3% and 27.5%, respectively, according to Ward’s.

“These are strong results that validate our progress,” Docherty says.

Fleet sales accounted for 31.5% of GM’s total deliveries, notably higher than the auto maker’s 25% target. Henderson attributes the bump to pent-up demand among buyers who could not afford to replenish their fleets last year.

emayne@wardsauto.com