Anglo-Swedish pharmaceuticals giant AstraZeneca said Thursday that net profits sank 37 percent last year, hit by the expiry of drug patents and \"tough\" markets, and warned revenues would fall further in 2013. Earnings after taxation dived to $6.297 billion (4.645 billion euros) in 2012, compared with $9.983 billion in the previous year, AstraZeneca said in a results statement. Revenues meanwhile tumbled 15 percent to $27.973 billion and were also expected to experience a \"mid-to-high single digit percentage decline\" in 2013. \"Our performance in 2012 reflects a period of significant patent expiry and tough market conditions globally,\" said new chief executive Pascal Soriot, who took the helm at the group late last year. \"Despite the challenges we face, I am excited about AstraZeneca\'s fundamental strengths which will be key in returning the company to growth and achieving scientific leadership while maintaining our reputation for strong financial discipline.\" The London-listed company faces crucial patent expires up until 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 key anti-cholesterol drug, Crestor, in 2016. Frenchman Soriot was previously a senior executive at Swiss drugsmaker Roche took up his role at the start of October after the resignation of American David Brennan. Brennan had already announced plans to cut 7,300 jobs by 2014 in a bid to improve profitability at the firm, which has come under heavy pressure in recent years from generic drugs competition.