LONDON (AP) - AstraZeneca PLC could have to delay the rollout of its new infant lung drug in the United States because the Food and Drug Administration has asked for more information about the medicine before allowing it on the market.

AstraZeneca said Friday that the FDA had requested more information on Motavizumab, a drug used to prevent a type of lung infection in babies.

AstraZeneca had been planning to get Motavizumab, used to prevent respiratory syncytial virus, to market in the second half of 2009 - in time to catch the next winter flu season.

It now plans to answer the FDA's questions before the end of the first half of the year, but it is unclear whether that will give the company enough time to get the drug to market on time.

"We're not yet speculating on what impact it will have on a possible launch date," said Sarah Lindgreen, a spokeswoman for AstraZeneca.

However, analysts were widely unconcerned about the potential delay's impact on AstraZeneca's sales because one current drug used to prevent respiratory syncytial virus, Synergis, is also produced by AstraZeneca.

Shares rose 5.3 percent to close at 2,445.00 pence in London.