Anglo-Swedish pharmaceuticals giant AstraZeneca said Thursday that second-quarter profits sank, hit by the expiry of key drug patents, tough conditions and competition from generic drugmakers. Earnings after taxation dived 24 percent to $1.61 billion (1.33 billion euros) in the three months to the end of June, compared with $2.11 billion in the same period of 2011, AstaZeneca said in a results statement. However, the performance comfortably beat market expectations of $1.45 billion, according to analysts polled by Dow Jones Newswires. \"Generic competition and challenging market conditions reflected in lower second quarter revenues,\" AstraZeneca said in the earnings release. Revenues meanwhile slumped 21 percent to $6.66 billion over the reporting period, caused largely by the loss of patent protection on key drugs. \"As we expected, the loss of exclusivity on some key brands and tough market conditions have resulted in a decline in revenue and earnings in the second quarter,\" added interim chief executive Simon Lowth. AstraZeneca is searching for a new permanent chief executive after David Brennan left the company at the start of June. Lowth, who is chief financial officer, is Brennan\'s temporary replacement. The company faces crucial patent expiries between 2012 and 2015 on drugs such as schizophrenia treatment Seroquel and heartburn and ulcer drug Nexium. It will also suffer the loss of patent protection in the United States for its best-selling anti-cholesterol drug, Crestor, in 2016.