Bermuda-based reinsurer, Axis Capital Holdings, Ltd posted second-quarter earnings that fell below analysts’ estimates as its net investment income fell.The company, which is a global provider of speciality lines of insurance and reinsurance reported an operating profit of $113 million, or 90 cents per share — three cents off Wall Street expectations. It was however, much higher than the $83 million, or 65 cents per share, operating income Axis reported in the second quarter of 2011.The company, which also provides accident and health insurance, reported net income of $168.2 million, or $1.35 per share, up from $101.1 million, or 79 cents per share, a year earlier.Net premiums earned rose one percent to $850.6 million, while net investment income fell 26 percent to $74.4 million.Axis’ reinsurance segment reported an underwriting profit of $95 million for the quarter, compared to $9 million last year.The insurance segment reported underwriting income of $25 million, up $5 million from last year.Diluted book value per common share of $40.55 at June 30, 2012, an increase of three percent during the quarter and ten percent from June 30, 2011.“We are pleased to report diluted book value per share, at $40.55, reached a new record at the end of the second quarter,” said Albert Benchimol, chief executive officer and president of Axis Capital. “Diluted book value per share growth, including dividends paid, was 12.8 percent over the last 12 months.”“The market environment for our businesses is showing ongoing improvement, and our underwriting operations are executing as expected in the current transitional market,” he added. “Growth is strong in markets that have shown improvement in pricing and in lines where investment in product or geographic expansion in recent years is gaining traction.“In other areas, which are for the most part stable or showing modest improvement, we have been actively optimising portfolio composition to expand margin. We are confident that we have strategically and tactically positioned ourselves to deliver continued significant value growth to shareholders.”Axis shares, which have risen almost 36 percent since they touched a low of $24.80 last September, closed at $32.86 yesterday on the New York Stock Exchange.