Europe\'s biggest bank HSBC said on Tuesday that group net profits hit $2.58 billion (1.98 billion euros) in the first quarter, down 38 percent on changes to debt valuation, while pre-tax earnings soared. The London-headquartered bank said the drop reflected \"adverse credit spread movements on the fair value of our own debt\" and partly owing to a higher tax charge. Stripping out the exceptional charges, HSBC said pre-tax profits jumped by 25 percent to $6.8 billion in the three months to March 31 compared with the first quarter of 2011. \"We have had a good start to the year,\" HSBC chief executive Stuart Gulliver said in the group\'s earnings statement. \"Underlying profit before tax increased by $1.4 billion, driven by increased revenues.\" Gulliver added that markets remained \"volatile with high levels of debt and regulatory and political uncertainty in developed economies, contrasting with an encouraging outlook in faster-growing markets. \"Our performance in April has been satisfactory, and we remain confident that we will deliver on executing our strategy,\" he said. Founded in Hong Kong and Shanghai in 1865, HSBC in the process of reducing the bank\'s global workforce by 30,000 over two years to 2013.