LONDON (Bloomberg) Bermuda-based Catlin Group Ltd said first-quarter sales rose 11 percent, helped by its US and Bermuda units.Gross written premiums climbed to $1.41 billion in the first three months of the year from $1.27 billion in the same period in 2010, the firm said in a statement today. The insurer’s estimate of $375 million in losses from catastrophes remain unchanged in the period.“Catlin is well-positioned to take advantage of underwriting opportunities as they develop,” chief executive officer Stephen Catlin said in the statement. The insurer “is in an excellent position, and we continue to look ahead with confidence”.Fellow Lloyd’s insurers Amlin Plc and Hiscox Ltd this week forecast premium rate will increase later in the year after earthquakes in Japan and New Zealand eroded firms’ natural catastrophe budgets.Catlin said last month it expected to pay about $200 million in claims related to the Japanese earthquake in March. The firm’s pretax profit was $406 million in 2010.