The new wagon - or 'Sports Tourer' - will variously wear Vauxhall or Opel badges, depending upon the market.
The wagon unveiling follows an early June debut for the new Astra hatch; both models will be on sale in Europe before the end of the northern autumn.
GM’s headline improvements for the new Astra wagon include a sizable weight-loss of 200kg over the outgoing model, with exterior dimensions that match its predecessor.
But despite being no bigger externally, with measurements of 4702mm long, 1871mm wide and 1499mm high, the new Astra boasts an extra 26mm of headroom in the front and 28mm in the rear.
The cargo area is also bigger, with a new capacity of 1630 litres with the 40/20/20 rear seats folded - up from 1550 litres.
A wide range of engines will be available for the European market, with the new wagon using most of the powerplant line-up from the Astra hatch.
Power outputs range from 74-147kW with torque figures measuring up to 300Nm. Engine choices will include a 2.0 litre ‘Whisper’ turbo-diesel and an all-new 1.4 litre turbo-diesel, while a 1.0 litre three-cylinder petrol engine is also a possibility.
Inside, the new wagon gets an updated version of the OnStar connectivity system including 4G compatibility with Apple CarPlay and Android Auto, and safety features include traffic sign recognition, forward collision alert, autonomous emergency braking and lane-keep assist.
Outside, an automatic tailgate is now available which can be operated by a kicking motion under the rear bumper, and the new model gets LED headlights.
While the new Astra hatch will eventually make its way to Australia wearing Holden badges, the outlook for the wagon is unclear.
Holden’s Cruze sedan and wagon (along with the Cruze hatch) are currently serving the carmaker in the small vehicle segment, and are likely to continue until at least 2017 when Holden ceases local manufacturing.