Anglo-American team United Autosports has withdrawn its two previously announced McLaren MP4-12C entries from the 2013 Bathurst 12 Hour.

The team will instead return to Mount Panorama with an Audi R8 Ultra, which replaces the LMS specification Audi that the team campaigned at Bathurst this year.

The news follows United Autosport’s decision to park its troublesome McLarens from the 2012 Blancpain Endurance Series in order to prepare for a full assault on next year’s British GT Championship.

“To be ready for the start of the 2013 season, the cars (McLarens) will be needed for a full program of testing and development, something that cannot be achieved whilst the cars are in transit on the high seas,” a United Autosports spokesman said in a statement.

“United Autosports are very pleased to announce that they will be bringing their brand new Audi R8 Ultra car to race in Bathurst. This is a considerable upgrade to the Audi R8 LMS car that the team raced in the 2012 race, with body work, chassis and aerodynamic enhancements that gives the car greater speed and stability for the challenging Bathurst circuit.”

The United car is one of five Audis to appear on the latest entry list circulated by Bathurst 12 Hour organisers today. A single entry from fellow international squad Phoenix Racing will also be joined by the local Melbourne Performance Centre-run cars owned by Peter Conroy, Rod Salmon and Mark Eddy.

Other changes to the Class A line-up from the previous list released in July include the addition of American squad CJ Racing (Porsche GT3 Cup Car) and Australian GT Championship runners Lago Racing (Lamborghini Gallardo) and Trofeo Motorsport (Corvette Z06).

Maranello Motorsport’s Ferrari meanwhile is no longer entered, leaving the Malaysian Clearwater 458 as the only representative of the Italian marque.

Entries for the February race remain open until December.

See below for the latest list released by race organisers today