Amazon has thrown down the gauntlet to sports specialists as it expands its range in the category in expectation of a spending surge during the Olympics.

UK managing director of the online giant Chris North said: “We’re expecting our sporting goods store to see strong growth with the Olympics coming up.

“We’re building our breadth in the area. We’ve scratched the surface of what we can offer.”

North said the retailer would offer a wider range of specialist sporting goods and added that shoppers can buy equipment such as javelins on its UK site.

Expanding ranges is a key plank in Amazon’s growth strategy in the year ahead. North said it is concentrating on greater depth in existing product ranges.

He said it was hiring buyers across its categories to help growth.

Over Christmas, jewellery, toys and perfume were its biggest growth areas.

North said: “It’s amazing that three of our biggest areas we weren’t even in a few years ago.”

The online giant suffered a sharp drop in group full-year profits despite soaring sales.

Group sales jumped 41% in 2011 to £30.4bn, while profits plummeted 45% to £399m as the retailer continued to invest in the business, including its investment in range expansion, its Kindle device and fulfilment infrastructure in the UK.

Amazon warned it could make a group operating loss of up to £126.4m in its first quarter.

North declined to forecast when the retailer would return to profit growth.

Sales in its last quarter were up 35% to £11bn and profits dropped 58% to £111.8m. International sales were up 37% to £4.76bn over the quarter.

The Kindle was the UK site’s top-selling item over Christmas with twice as many devices sold in the festive run-up compared to last year.