A Texas senator is blocking confirmation of the nominee for the Army’s top weapons buyer until the Defense Department pledges to take action against a Russian company supplying arms to Syria’s Assad regime.

Republican Senator John Cornyn has invoked a senatorial prerogative to place a “hold” on Heidi Shyu, President Barack Obama’s nominee to be the Army’s assistant secretary for acquisition, technology and logistics, according to an aide to the senator who spoke on condition of anonymity because discussions about the dispute are being held in private.

Cornyn is leading a Senate effort pressuring the Department of Defense to stop doing business with Rosoboronexport, Russia’s state-run arms trader. The Army has a $375 million, no-bid contract with the company to buy 21 Russian-made Mi-17 helicopters for Afghanistan’s air force that it says only Rosoboronexport can provide.

“The DoD and the Army have refused to look for alternatives, even as Rosoboronexport continues to arm the Assad regime,” Cornyn said in an e-mailed statement. “The DoD and the Army must end their practice of handing no-bid contracts to this problematic Russian broker and instead conduct full and open competition for all future Mi-17 procurement.”

The Senate by tradition permits any senator to place a hold on a nomination for a period of time to gain leverage in a dispute with the executive branch.

Electrical Engineer

Shyu, who is serving as the Army’s acting acquisition chief, was a vice president of Raytheon Co., a defense contractor, before joining administration in November 2010, according to a White House announcement when Obama nominated her in February.

Shyu also has served as vice chairman of the Air Force’s scientific advisory board. She received bachelor’s and master’s degrees in mathematics from the University of New Brunswick and the University of Toronto, both in Canada, and a master’s degree in electrical engineering from the University of California, Los Angeles. She began her career in 1978 as an engineer for Hughes Aircraft Co.

The Army has taken delivery of nine helicopters, with six more awaiting shipment and another six to be delivered by May 31. The U.S. has an option to buy an additional 12 Russian helicopters for the Afghans, who have been flying them for decades, Pentagon officials told Cornyn. The Senate Armed Services Committee estimates the purchases could reach $1 billion.

Against Civilians

Pentagon Undersecretary for Policy James Miller acknowledged in a March 30 letter to a lawmaker “that Rosoboronexport continues to supply weapons and ammunition to the Assad regime” and “there is evidence that some of these arms are being used by Syrian forces against Syria’s civilian population.”

A representative of the Moscow-based company said June 8 that it’s also bidding to sell ammunition to the U.S. armed forces.

Five suppliers competing for a U.S. military contract have invited Rosoboronexport to act as a subcontractor, it said in an e-mailed statement. The ammunition would be used in international coalition operations, the company said.

Separately, Secretary of State Hillary Clinton today said the Assad regime is set to receive a new order of attack helicopters from Russia.

“We are concerned by the latest information we have that there are attack helicopters on the way from Russia to Syria, which will escalate the conflict quite dramatically,” Clinton said without elaboration at a conference today in Washington.

‘Deeply Troubled’

Cornyn, a member of the Senate Armed Service panel, wrote in a letter yesterday to Defense Secretary Leon Panetta that he remained “deeply troubled that the DoD would knowingly do business with a firm that has enabled mass atrocities in Syria.”

“I support the president’s call for the end of the Assad regime, as well as the goal of stopping the flow of arms to Syria,” Cornyn wrote. “But the DoD’s ongoing business relationship with Rosoboronexport undermines both.”

Panetta spokesman George Little in an e-mail today said the secretary has received Cornyn’s letter and “will reply promptly.”

Aircraft ‘Crucial’

“These aircraft remain crucial to the development of Afghanistan’s Air Force capability and therefore important to our mission of ensuring that Afghan forces can ultimately defend their own sovereignty,” Little said.

The Rosoboronexport contract “is the only legal method to purchase the military version of the Mi-17 and to provide an appropriate measure of flight safety and airworthiness,” he said. “This procurement complements the existing aircraft inventory, completing the number of helicopters necessary to establish the Afghan Air Force’s rotary-wing capability for ensuring its future security.”

Pentagon spokesman Navy Captain John Kirby said at a press conference today that the Syrians are “killing their own people.”

“So I got the connection to Russia,” he said. “We’re going to take the senator’s concerns very seriously, but let’s not let the Assad regime off the hook here. It’s less important what they’re buying than it is what they’re doing with what they’ve got.”

House-Passed Ban

The Senate committee in the report on its fiscal 2013 defense authorization bill directed the Government Accounting Office to review the contract.

The House, in the version of the measure it passed, adopted an amendment by Representatives Rosa DeLauro, a Connecticut Democrat, and Kay Granger, a Texas Republican, that would prohibit future contracts to Rosoboronexport.

Their amendment would prohibit the Defense Department from awarding a contract to supply helicopters to the Afghan security forces to any entity “controlled, directed or influenced” by a state that has supplied weapons to Syria or a state sponsor of terrorism.

The Senate defense measure is S. 3254. The House-passed version is H.R. 4310.