US pharmaceuticals giant Pfizer said Tuesday that its second-quarter profit rose 5 percent from a year ago to $2.6 billion, slightly beating analysts\' expectations. The company\'s revenues for the April-June period were $17.0 billion, down one percent from the same period last year, the New York-based company said in a quarterly earnings report. Diluted earnings per share were 60 cents, just above the consensus analyst forecast of 59 cents. \"Our performance this quarter was in-line with our expectations,\" chief executive Ian Read said in a statement. Pfizer\'s \"results were impacted by losses of exclusivity of several key products in certain geographies,\" Read said. Pfizer is facing uncertainty as some of its top-selling drugs are set to lose patent protection in the near future, notably anti-cholesterol drug Lipitor, which will go off-patent in the United States in November. The company said its emerging markets unit lost $59 million in sales as a result of several key medicines, including Lipitor and sexual-potency drug Viagra, being opened up to competition in Mexico and Brazil in 2010. Shares of Pfizer fell 1.2 percent in pre-market trading after the earnings report was released.