BMW has released official images of the updated version of its flagship SUV - the BMW X6 - which will land in Australia in the middle of 2012.

The big news for the upgraded, 2012 BMW X6 is the addition of the new X6 M50d variant, which comes under the brand's recently revealed BMW M Performance Automobiles range.

The X6 M50d will be powered by a 3.0-litre triple-turbo diesel engine. Producing 280kW of power and 740Nm of torque, the new variant can sprint from 0-100km/h in 5.3 seconds, yet uses just 7.7 litres of fuel per 100km under European combined standards. That makes it one-tenth quicker than the petrol-powered twin-turbo V8 xDrive50i, and almost 40 per cent more fuel efficient.

The M50d will slot into the range between the xDrive50i and the X6 M, suggesting a starting price of around $165,000 before on-roads.

BMW Australia will continue to offer the full X6 range, which also includes the xDrive30d, xDrive35i and xDrive40d variants. Engine outputs and fuel consumption data remains unchanged for all continuing variants. Pricing is expected to closely resemble the current line-up, which ranges from $109,9900 to $185,000.

The mid-life X6 upgrade is largely cosmetic, with small changes to the front, rear, wheel designs and interior finishes.

BMW's designers aimed to emphasise the car's width, giving attention to the fog lights, air intakes, bumper design and kidney grille. Adaptive LED headlights are available as an option to the standard xenon units. The taillights now incorporate twin LED banks, mirroring others in the modern BMW range. The xDrive50i gets new 19-inch light alloy wheels.

The standard leather can now be optioned in Vermillion Red, while those who opt for the nappa leather upholstery can select between Black and Ebony White.

BMW will confirm pricing and specification details of the X6 update closer to its Australian launch.

BMW Australia sold 343 X6s in 2011, down 8.3 per cent compared with 2010. Its share of the luxury SUV segment slipped from 1.5 per cent to 1.1 per cent.