Amazon has taken a $170 million charge related to its Fire smartphone business, amid reports the device has failed to find buyers.

In a Q3 conference call, Tom Szkutak, its CFO, said this was primarily related to “Fire phone inventory evaluation and supplier commitment cost”.

The retail giant announced its debut smartphone in June 2014, and it features a number of user interface innovations as well as being supported by Amazon’s apps and content ecosystem.

But the device has met with mixed reviews, with reports that sales have been somewhat lacklustre.

Amazon recently extended availability of the device to the UK and Germany, ahead of the lucrative Christmas holiday sales period.

More positively, Szkutak noted that the company has refreshed its tablet line, and “there is some really great price points for customers on the tablet side” – including a $99 entry-level device.

Amazon’s third-quarter net loss widened to $437 million, from $41 million a year ago. Revenue also fell short of expectations. Net sales rose to $20.58 billion, but that lagged forecasts for $20.84 billion, according to Thomson Reuters.