UPDATE 1-Balfour Beatty unit appoints counsel to probe U.S. Air Force base allegations

(Adds details on allegations, share movement)

July 15 (Reuters) - A unit of British infrastructure group Balfour Beatty has appointed Hunton Andrews Kurth LLP to work with the U.S. Air Force and other authorities to investigate allegations that it falsified maintenance records at a U.S. Air Force base.

The appointment of an outside counsel comes days after U.S. Senator Elizabeth Warren called for an official inquiry and demanded answers from the Air Force and one of its top housing contractors about practices at the Tinker base in Oklahoma.

A Reuters-CBS News report in June described how Balfour Beatty Communities (BBC) falsified maintenance records at the Tinker base to help it secure Defense Department bonuses, based on a review of company records, Air Force reports and interviews with former workers.

"We take the allegations in relation to Tinker Air Force Base very seriously as they would contravene our company-wide Code of Conduct," Balfour, among the U.S. military's largest housing providers, said.

"The allegations made do not reflect the culture or the work ethic of over 1,200 employees across Balfour Beatty Communities who are dedicated to maintaining the highest standards of conduct and service at all the military facilities," it added.

Reuters and CBS said BBC kept two sets of maintenance records at the base. An official set of electronic records, shown to the Air Force, listed prompt responses to maintenance requests. The other, a handwritten log not shared with the military, accurately showed the company consistently took much longer to finish jobs.

In response to the report, Balfour said it had cooperated fully with inquiries by the Air Force and other government agencies into its business.

"As an organization, BBC has not and does not condone the falsification of records in any way," it said at the time.

Balfour's shares were 1.8% lower at 234.4 pence at 1306 GMT.

(Reporting by Samantha Machado and Noor Zainab Hussain in Bengaluru; Editing by Kirsten Donovan and Mark Potter)