NEW YORK--News Corp has hired more PR support, naming two firms to help it deal with US scrutiny of its phone-hacking scandal.

Public affairs heavyweight Glover Park has been brought onboard to provide government and policy relations, amid concerns that the US government may open an investigation. The FBI has begun a preliminary enquiry into allegations that News Corp hacked the phones of 9/11 victims.

In addition, News Corp has retained financial specialist Sard Verbinnen, to help reverse the downturn in investor sentiment. The company’s stock price has declined by around 17 percent since 1 July, although shares rose by 5.6 percent today, while Rupert and James Murdoch made a dramatic appearance in front of a Parliamentary select committee.

The appointments were confirmed by News Corp’s US SVP of communications and corporate strategy Julie Henderson, in an interview with Bloomberg.

The two firms join a PR war room that includes Edelman UK, and Steven Rubenstein. The Holmes Report also understands News Corp has worked in the past with PSB, the polling firm founded by Burson-Marsteller CEO Mark Penn, on reputation research.

Responding to a question from today’s committee about the advice received before the hearing, James Murdoch said: “We were advised fundamentally to tell the truth, and be as open and transparent as possible.”