London-based Finsbury and Kekst, which has New York headquarters, are working under the lead counsel of German consultancy Hering Schuppener. Consumer PR assistance in the US will continue to be provided by Edelman, with which it has a longstanding relationship.
Finsbury partner Rollo Head is leading that agency's brief with the car maker.
The appointments follow revelations in the US that Volkswagen installed software in its cars to disguise emission levels, which led to the resignation on Wednesday last week (23 September) of global CEO Martin Winterkorn.
In a statement issued yesterday, VW announced an "action plan" to "correct the emissions characteristics of diesel vehicles". This is expected to apply to 11 million cars worldwide, the company said.
The statement added: "In a first step, the customers affected will be informed that the emissions characteristics of their vehicles will be corrected in the near future. All vehicles are technically safe and roadworthy.
"Under the action plan, Volkswagen and the other group brands whose vehicles are affected will present the technical solutions and measures to the responsible authorities in October. Customers with these vehicles will be kept informed over the coming weeks and months. All of the group brands affected will set up national websites to update customers on developments."
According to analysts, the refit could cost $6.5bn (£4.3bn). VW has lost about 40 per cent of its market value since US regulators first said it tried to sidestep emissions rules for its diesel cars.
At a press conference on Friday (25 September) Winterkorn's replacement, former Porsche boss Matthias Muller, said the scandal was the result of "engineers" and "technicians" but did not say how many people had been suspended as a result.
It has been reported across German and international media that the firm was warned about the software on multiple occasions in recent years.