The car has been revealed at the New York International Auto Show and will arrive in New Zealand late this year.
Until now, current generation Impreza WRX STI has been available only as a hatch. The hatch STI will continue in the model range for 2011.
"We can confirm a four-door Impreza WRX STI will join our model line-up later in the year,” said Graeme Woodlands, the Managing Director of Subaru of New Zealand.
He said further specification and pricing will be announced at launch time.
Subaru’s latest developments follow recent news that the wide body sedan and hatch versions of the Impreza WRX are also being launched later this year.
The symmetrical All Wheel Drive Impreza WRX STI featuring a 221 kilowatt turbocharged Boxer engine will also have revised suspension, spring and damper rates with a 5 mm lower vehicle ride height.
Mudguard flares emphasise the wider body design and there are new bumpers, grille and rear diffuser.
The wide body design further distinguishes Subaru’s turbocharged Impreza variants from the normally aspirated models.