Audi has released details and pictures of its 2012 A1 Sportback – the five-door version of its Mini rival.

The more practical version of the three-door A1 that was launched locally in December 2010 will go on sale in Australia in mid 2012.

It will expand an A1 line-up that has already been a sales success both globally and in Australia and will become Audi’s best-selling model, according to the car maker.

The A1 Sportback is the same length as the 3.95m-long three-door A1 but is 6mm taller and wider to bring slightly more head and shoulder room.

Four seats are again standard, though the Sportback is offered with an optional fifth seat that will available in Australia at no extra cost.

Practicality otherwise remains unchanged, with boot capacity still 270 litres – expandable to 920 litres with the rear seats folded down.

The two extra doors are obviously one of the differentiators between the two A1 models and add only about 25kg to the five-door’s kerb weight.

A1 Sportback customers, however, have an additional paintwork option where they can pay extra for the upper section of the car – including the roof, roof arches and rear spoiler – to be finished in a contrasting colour to the main body.

The three-door A1 offers only optional roof arches in a contrasting colour.

Engines in Europe again include three petrols and three diesels, and Audi Australia says it is considering all options. For the three-door A1, the company selected a 90kW 1.4-litre turbo petrol four-cylinder, 136kW 1.4-litre turbocharged and supercharged four-cylinder and a 66kW 1.6-litre turbo diesel four-cylinder.

The 2012 Audi A1 Sportback, which as with the three-door is related to the Volkswagen Polo, is likely to carry a small premium over the three-door that starts at $29,990 for a 1.4 TFSI Attraction manual.

In Europe, the entry-level Sportback will cost about $1550 more than the base three-door.