By Simon Kennedy, MarketWatch

LONDON (MarketWatch) -- Shares of drug giant AstraZeneca PLC dropped sharply Friday after a further delay in the potential approval of the firm's Brilinta heart drug, while worries about losses in Ireland also weighed on the banking sector, pulling the U.K.'s benchmark index down.

The FTSE 100 fell 0.3% to 5,873.96, as gains for mining companies as well as some oil and telecom stocks helped limit losses for the index.

Shares in AstraZeneca (AZN) slumped 5.4% after the U.S. Food and Drug Administration asked for additional analysis of data from a study of Brilinta.

Analysts said the demand for extra analysis is likely to delay final approval of the drug by six to twelve months.

That's a particular worry for AstraZeneca because patent expiration will expose several of its drugs to generic competition in the coming years and U.S. Brilinta sales are one of only a few potential sources the company has to replace lost revenue, said analysts at Jefferies International.

"This delay will come as a disappointment to many and may also start to raise uncertainties about the potential scale of the product's likely commercial success," the broker said in a note to clients.

Jonathan Jackson, head of equities at Killik & Co., said the patents expiring over the next six years account for more than half of the company's sales.

"Although the company remains confident in the outlook for Brilinta, at best the launch will be delayed by up to a year. At worst, it will be rejected. Either way, the chances of approval in the U.S. have probably reduced and the prospect of more onerous labelling may hamper its sales potential," Jackson said.

Bank stocks also weighed on the main U.K. index Friday as European leaders continued to meet in Brussels to discuss the sovereign-debt crisis.

Shares in Lloyds Banking Group (LYG) dropped 3.5% after it warned that it had seen "a further significant deterioration" in its Irish business.

The bank said around another 10% of its 26.7 billion pound Irish portfolio likely became impaired over the second half of the year and that the total impairment charge for the year related to Ireland will be around  £4.3 billion.

Shares in Royal Bank of Scotland Group (RBS), which has an even bigger exposure to Ireland that Lloyds does, fell 4.9%.

Bank stocks were also weaker across the rest of Europe, dragging most of the continent's major indexes lower.

Mobile network operator Vodafone Group PLC was a strong performer. Shares in the group rose 1.3% after Nomura named the stock as its top pick among large-cap telecommunications companies, due to its cash flow and potential dividend upside.

Software firm Autonomy Corp. rose 4.2% as technology stocks got a lift across Europe from Oracle Corp.'s (ORCL) strong earnings and following a report on Thursday that Oracle or Microsoft Corp. (MSFT) could make a bid for the company.

Mining stocks also reversed earlier losses to trade higher as commodity prices edged up. Vedanta Resources PLC rose 2% and Lonmin PLC rose 1.3%.

Most oil and gas stocks advanced, with BG Group rising 0.9% and Royal Dutch Shell (RDSA) up 0.6%.

Outside the main FTSE 100 index, shares in Punch Taverns PLC jumped 14% after the company said its improved trading momentum has continued in recent weeks, despite the impact of severe weather.

 
 
Punch Taverns (LSE:PUB)
Historical Stock Chart
From Oct 2024 to Nov 2024 Click Here for more Punch Taverns Charts.
Punch Taverns (LSE:PUB)
Historical Stock Chart
From Nov 2023 to Nov 2024 Click Here for more Punch Taverns Charts.