* World's No. 2 and 3 reinsurers post Q1 profits
* Reinsurance prices weaken over first quarter
* Reinsurers focusing on profitability, not volume (Adds detail, quotes, analyst, share price)
By Alice Baghdjian and Caroline Copley
ZURICH/FRANKFURT May 7 (Reuters) - Swiss Re and Hannover Re, the world's no. 2 and 3 reinsurers, said they saw lower prices in natural disaster reinsurance and April renewals, as they beat profit expectations in the first quarter.
Fewer serious natural disasters, as well as competition from pension funds pouring money into the reinsurance industry, have crimped the pricing power of reinsurers, which help primary insurers cover the cost of major damage claims in return for part of the premiums.
Both insurers stressed on Wednesday they would focus on profitable areas of business rather than growing premium volume, to try to ride out a decline in pricing.
"We are not slaves to volume, and we will certainly not write business to fulfill some top line aspirations," said Swiss Re Chief Executive Michel Lies.
The Zurich-based reinsurer said prices for natural catastrophe reinsurance had felt the greatest price pressure for the quarter, while other segments were mixed. It declined to give specific detail, playing down the impact of weaker prices when annual reinsurance contracts with insurance company clients were renewed in April.
"Prices are coming down but I would like to stress they are still at attractive levels," Lies said.
The Swiss reinsurer said it wrote less natural catastrophe business but group volumes rose 14 percent during April renewals on tailored large transactions and expansion into casualty, which had seen profitable growth in all regions.
Hannover Re said it accepted a decline in premium volume after a "fiercely competitive" first quarter in property and casualty, which covers the non-life reinsurance business, to focus on more profitable areas.
The German reinsurer's total gross premiums for non-life declined 4.1 percent in the first three months of the year to 2.1 billion euros ($2.93 billion)compared to last year.
Shares in Swiss Re and Hannover Re had barely risen by 1200 GMT, trading up 0.3 percent and 0.8 percent, respectively.
"At this stage, we have a preference for primary insurers over reinsurers because of the pricing dynamics going forward," said Helvea analyst Daniel Bischof. "In our view, Swiss Re shares will continue to be driven by the challenging renewals outlook."
Munich Re, the world's No.1 reinsurer, said last month it felt increasing price competition during April's renewals but has fared better than the overall market. It is due to report first quarter results on May 8.
Higher investment income lifted net profit at German rival Hannover Re, which unexpectedly rose to 233 million euros in the first quarter.
Quarterly net profit at Swiss Re fell 13 percent on weaker earnings in its life and health arm, although fewer natural catastrophes meant the fall was less than expected.
Swiss Re reported a combined ratio, an insurance industry measure of profitability weighing payouts against premium income, of 78.8 percent in its property and casualty arm compared with 69.7 percent a year earlier.
The Zurich-based firm said it had appointed Patrick Raaflaub, the former chief executive of Switzerland's financial regulator FINMA, as the group's chief risk officer, effective Sept. 1. ($1 = 0.7177 Euros) (Editing by Louise Heavens)