Astar, a DHL vendor and shipping customer, made the assertion to a U.S. House panel in written testimony by Chief Operating Officer Gary Hammes, citing a comment by a UPS salesperson that DHL service would become “substandard” under the new alliance.

“It is our belief that these sales calls are working,” Hammes testified. DHL volume has decreased “significantly,” possibly as much as 40 percent, since the May 28 announcement of a plan to have its U.S. air freight flown by UPS, Hammes said in his testimony and in an interview.

Hammes’s comment opened a new front in the criticism of the UPS-DHL partnership by groups including labor unions and lawmakers from Ohio, where Astar and another DHL vendor operate hubs. The House Transportation and Infrastructure Committee held a hearing on the effects of the DHL-UPS plan.

Questions about the future of DHL’s money-losing U.S. operations have hurt volumes this year, which is why the company wants to conclude the UPS agreement, DHL Express Chief Executive Officer John Mullen said in an interview.

No Directive

A drop in volume of as much as 40 percent “is not right,” said Mullen, who declined to cite a specific figure. While individual UPS salesmen may cite the May 28 accord to try to win business, “I’m absolutely confident it’s not a sanctioned management directive,” he said.

UPS spokesman Malcolm Berkley called Hammes’s statements “unsubstantiated” and said the world’s largest package- delivery company isn’t using its planned collaboration with DHL to compete more vigorously than usual for customers.

UPS said May 28 it was working on a 10-year agreement to take over U.S. shipments from Astar and Air Transport Services Group Inc.’s ABX unit, which would bring UPS as much as $1 billion in annual revenue.

Closely held Astar is 49 percent owned by DHL. Miami-based Astar gets 90 percent of its revenue from DHL, and all of its 1,007 employees as of May 28 would lose their jobs should the UPS-DHL plan be completed, Hammes said in his testimony.

DHL, aside from being a vendor, is also a customer of DHL’s overnight express services and it was in that context the UPS sales call was made, Hammes said in his testimony.

Unions and Ohio lawmakers have said the UPS-DHL alliance would cut jobs in the town of Wilmington, where Astar and ABX have hubs.