Increasing dominance in the cholesterol drugs market and financial flexibility provided by acquisitions helped Pfizer beat Wall Street expectations on its first-quarter earnings.

Excluding one-time charges and asset sale gains, Pfizer's first quarter earnings rose 27 per cent to 52 US cents per share, compared with 41 cents in the same period a year ago.

Sales rose 47 per cent to $12.5 billion (€10.49 billion) in the quarter, due to Pfizer's acquisition of rival Pharmacia, strong product sales and a weaker US dollar. Pfizer, which employs more than 1,000 people in Ireland, strengthened its lead as the world's largest drugmaker last April when it acquired Pharmacia for about $57 billion. Results from Pharmacia are not included in last year's first quarter.

The group's aggressive acquisition strategy has given it synergies allowing it to cut costs while building a diversified product portfolio that can shield it against surprises. It also has brought it the most lucrative drug in the world, Lipitor for cholesterol. Lipitor led Pfizer's strong sales growth with a 19 per cent increase to $2.5 billion in the first quarter, which saw Pfizer and Lipitor dominate the cholesterol market.

However, charges from acquisitions affected Pfizer's first-quarter net profits. Including $1.5 billion non-cash charges and other items, Pfizer's net profits fell 50 per cent to $2.3 billion, or 30 US cents per share, from $4.7 billion, or 76 US cents, last year.