UK stocks opened lower on Tuesday as investors continued to fret about US-China trade relations and geopolitical tensions in Iran.

At 0841, the benchmark FTSE 100 index was down 18.70 points, or 0.3%, at 7.397.99.

Carpet seller Carpetright gained 8.2% after it reported a return to like-for-like sales growth in its new financial year.

Services company Petrofac dropped 4.4% as it warned that it expected its annual margins at its engineering and construction business to be at the lower end of its guidance range.

Anglo American gained 0.2% despite the value of rough diamond sales for De Beers' fifth sales cycle of 2019 falling to $390m. Vehicle hire group Northgate gained 0.2% as it booked a 15% rise in full-year profit, having boosted sales and margins in both the UK and Spain.

Online music retailer Gear4Music shed 8.7% after it swung to a net loss, as gross margins fell in a 'highly competitive' market.

Health and social care provider Ashley House slumped 13% on warning that it might fail to meet market expectations, due to uncertainty over achieving financial close on three care schemes operated through its Morgan Ashley joint venture.

Specialist engineering group Pressure Technologies dropped 9% after it only swung to a modest first-half profit, despite improving conditions in the oil and gas sector boosting sales.

Paper products firm James Cropper fell 6.4% as higher pulp prices offset record revenue to send its annual pre-tax profit down to £2.6m, from £4.5m.

Home collected credit company Morses Club fell 2% on announcing that credit issued was slightly down so far this year.

Subsea cable protection company Tekmar jumped 12% as it swung to a full-year profit after winning new contracts in the booming offshore wind sector.