American Le Mans Series president has praised Audi following the announcement that the new R15 TDi won't race in the series in 2009.
Audi has been one of the biggest supporters of the series in recent years and has rewritten the record books with its run of success, which has seen it be the dominant force in the prototype ranks of the ALMS and at Le Mans.
With the current economic climate forcing teams and manufacturers to re-evaluate their plans for the new season, Audi elected to pull out of the ALMS on a full-time basis, although the R15 will make its race debut in the opening event of 2009 at Sebring.
Instead, the German manufacturer will focus on Le Mans, the DTM and its new R8 customer programme back in Europe but Atherton had nothing but praise despite the loss of one of the ALMS' biggest names.
"I cannot say enough about how great a partner, competitor and participant Audi has been since it first competed in the Series in 1999," he said. "We understand that the economic climate is forcing many companies to make very difficult decisions. We will welcome Audi back to the American Le Mans Series stage at the appropriate time to compete against our world-class group of race teams and manufacturers.
"Audi, along with Dave Maraj and his Champion Racing organisation, have established the benchmark for how a motorsports organisation should be run. They raised the game for all our competitors with their innovation, work ethic, professionalism and accomplishments, which are major reasons why the American Le Mans Series enjoyed its most successful season ever this year."
Audi campaigned its first full season in the American Le Mans Series in 2000 and by the end of the 2008 season, it had recorded 55 LMP1 class victories, including 30 consecutive wins from Sebring 2006 to Detroit 2008.
Audi also the Mobil 1 Twelve Hours of Sebring and Petit Le Mans nine times each.