LONDON, Sept 11 (Reuters) - AstraZeneca Plc (AZN.L: Quote , Profile , Research ) shares dipped on Monday after the second largest U.S. health insurer said it had decided to stop paying for the company's heartburn and anti-ulcer drug Nexium.

UnitedHealth Group Inc (UNH.N: Quote , Profile , Research ) said there were cheaper and equally effective options available, which it planned to use instead of AstraZeneca's top-selling medicine.

The decision is a setback for the Anglo-Swedish concern but a spokesman said the group would not be revising its 2006 or 2007 net sales projections as a result of the move.

Nexium raked in global revenues of $4.6 billion for AstraZeneca in 2005. UnitedHealth expects to save around $150 million a year from dropping Nexium, equivalent to roughly half the total amount it spends on all so-called proton pump inhibitor drugs for acid reflux disease at present.

Shares in AstraZeneca were off 0.6 percent at 32.81 pounds by 0800 GMT in a flat market for European drug stocks.

Source:
http://today.reuters.com/news/articlebusiness.aspx?type=health&storyID=nL11479793&from=business