SANTA MONICA, Calif. — Data analyzed by Edmunds.com revealed that General Motors has managed to maintain — and even grow — the loyalty rate of former Pontiac owners one year after the last remaining Pontiac dealers shut down for good.

The automotive Website found that 39.9 percent of Pontiac owners who traded in for a new car this year opted for a GM vehicle. This retention rate is eight percentage points greater than GM’s retention rate in 2010, and represents the highest retention rate since 2007.

This year, GM’s Chevrolet brand has been most successful in retaining former Pontiac owners, with 28.1 percent of them choosing Chevy as their new brand, according to the Website. Edmunds.com’s analysis also discovered that Chevrolet sales to former Pontiac owners were particularly strong in January and February of this year when GM made aggressive incentive plays to retain old customers and conquest new ones.

“Any time a manufacturer shuts down a brand, there’s a concern that its consumers will shift loyalties to another company,” says Michelle Krebs, senior analyst at Edmunds.com. “General Motors took a calculated risk that it could retain Pontiac drivers under its umbrella, and the gamble appears to have paid off — with even more success than they enjoyed in previous years when Pontiac was still an option for returning customers.”

Ford Motor Co., meanwhile, has been the most successful non-GM brand to conquest Pontiac owners this year. An estimated 9.4 percent of former Pontiac owners have jumped to Ford in 2011, but the rate is down from last year’s reported 12.4 percent. Honda and Toyota have each managed to conquest an estimated 7.4 percent of Pontiac customers, which is a lower rate than last year for both brands.