Unilever said on Monday that the attacks on the US would indirectly affect the performance of at least two of its businesses, contributing to a more cautious short-term trading outlook.

However, it still expects to achieve this year's target of "low double-digit" growth in earnings per share before exceptionals and goodwill amortisation, even though earnings are expected to be flat this quarter.

The Anglo-Dutch consumer products company was briefing analysts and investors on trading for the first two months of its third quarter.

Unilever said "the tragic events of September 11 pose particular challenges" for its perfumes arm, which include the Calvin Klein and Valentino brands, and for its US food service business, which supplies food to restaurants and canteens.

It said that those businesses were "already starting to feel the impact of a poorer economic environment".

September is a key period for shops to stock up on perfumes but this is likely to be affected by fears over consumer confidence.

The catering business is feeling the effect of some Americans' reluctance to eat out at the moment.

Unilever stressed that the affected businesses account for less than 4 per cent of turnover.

It also said that international demand for its products, which range from Lipton tea to Dove soap, generally tended to be resilient during times of uncertainty because they supplied consumers' everyday needs.

Unilever shares fell 21½p to 509½p. Like the shares of most food companies, they have so far proved to be relatively safe havens following the attacks.

The company said third-quarter sales growth should be nearly 4 per cent before acquisitions and disposals. Volume growth for its home and personal care products in some parts of Asia-Pacific and Latin America is likely to slow down because of price increases following currency devaluations.

Unilever said that it was looking closely at its advertising spending and would prioritise its most important products and innovations. It said it was also benefiting from cheaper advertising rates.