FRANKFURT (Reuters) - Volkswagen's (>> Volkswagen) premium carmaker Audi (>> Audi AG) announced its biggest management reshuffle in years on Monday as it seeks a fresh start in the aftermath of the diesel emissions scandal.

Audi, which is the biggest contributor of profits to VW, said it was replacing finance chief Axel Strotbek, production chief Hubert Waltl, human resources head Thomas Sigi and sales chief Dietmar Voggenreiter, effective Sept. 1.

Chief Executive Rupert Stadler, who has come under fire from the media and unions for his handling of the group's emissions scandal, remains in office, as expected.

The statement gave no reason for the shake-up.

People familiar with the matter had flagged the management reshuffle to Reuters. One said that Stadler had the backing of the Porsche and Piech families that control Volkswagen (VW), which is why his contract was extended by another five years in May.

Audi is grappling with car recalls, prosecutor investigations and criticism from unions and managers over the diesel emissions scandal and its performance since news of the affair broke in 2015.

Audi admitted in November 2015 that its 3.0 litre V6 diesel engines were fitted with an auxiliary control device deemed illegal in the United States that allowed vehicles to evade U.S. emissions limits.

Parent Volkswagen has agreed to spend up to $25 billion in the United States to address claims from owners, environmental regulators, states and dealers and has offered to buy back about 500,000 polluting U.S. vehicles.

Audi named VW manager Wendelin Goebel, a confidant of VW CEO Matthias Mueller and Audi's Stadler, to replace Sigi as personnel chief. Peter Koessler, the chief of Audi's plant in Gyor, Hungary, will succeed Waltl as head of production.

VW commercial vehicles sales chief Bram Schot will take over Voggenreiter's job, and CFO Strotbek will be succeeded by Alexander Seitz, who has held positions in Latin America and at Chinese joint venture SAIC Volkswagen, according to Audi.

(Reporting by Maria Sheahan; Editing by Christoph Steitz and Adrian Croft)

Stocks treated in this article : Audi AG, Volkswagen