London: British pharmaceuticals giant AstraZeneca on Thursday said third-quarter net profits tumbled by about a third as a large exceptional gain was not repeated.

Earnings after taxation dived 32 per cent to $686 million (Dh2.5 billion, €592 million) in the three months to September 30, AstraZeneca said in a results statement.

That compared with net profit of $1.01 billion for the same part of the previous year, when the group had enjoyed a large one-off tax gain.

AstraZeneca was boosted in 2016 by an exceptional tax benefit of $453 million following agreements on transfer pricing arrangements with British, Canadian and Swedish tax authorities for the period 2004-2016.

Total revenues meanwhile rose nine per cent to $6.2 billion in the third quarter of 2017, buoyed by a multi-billion-dollar deal unveiled in July to jointly develop key cancer drugs with Merck.

However, AstraZeneca’s product sales fell three per cent to $4.8 billion, hit by generic competition for blockbuster cholesterol-lowering drug Crestor in the key United States market.