Auto lease deals this year are expected to slip well below the 2-million mark for the first time in more than a decade, says Tom Webb, chief economist of Manheim Consulting, a branch of a major auction firm.

With a continued decline in new-vehicle deliveries and a further retrenchment of lease penetration rates, he’s estimating new lease originations will reach only 1.2 million units in 2009. That compares with a peak 3.7 million in 1999.

The effects of less leasing now will be felt in two to three years. “This is setting up the wholesale market for a dramatic falloff in off-lease volumes in 2011 through at least 2013,” Webb says.

Industry lease penetration rates are just above 10% this year. That compares with more than 20% in the beginning of 2008.

New-vehicle lease penetration rates, which began to fall sharply in second-half 2008, continued to decline in first-half 2009, according to Manheim tracking.

Given the reduced access to capital and the residual-risk exposure, it is unlikely leasing will soon, if ever, return to previous highs, Webb says in Manheim’s Mid-Year Used-Car Market Report.

But he adds that leasing remains an important financing option, especially for high-line vehicles and can be a “win-win-win” for auto makers, dealers and consumers, “if done right.”

Some major auto makers, notably Chrysler LLC and General Motors Co., abandoned leasing last year because of problems with financial stability and falling residuals on several vehicle models.

GM is inching back into leasing, but not to drive volume nor dramatically lower monthly car payments, says Mark LaNeve, the auto maker’s sales chief.