CNA Surety Corporation has reported a net income of $22.9 million, or $0.52 per diluted share for the first quarter of 2008, compared with $20.7 million, or $0.47 per diluted share for the same period in 2007.

According to CNA, the increase in net income reflects higher earned premium and higher net investment income, partially offset by higher underwriting costs.

For the quarter, gross written premiums decreased 1.5% to $116.6 million from $118.4 million posted in the corresponding quarter of 2007.

For the quarter ended March 31, 2008, the loss, expense, and combined ratios improved to 25.3%, 53.9%, and 79.2%, respectively, compared to 25.4%, 54.8%, and 80.2%, respectively, for the same period in 2007. The current ratios reflect the benefits of higher earned premium and lower reinsurance costs.

Net investment income for the period was $11.8 million, higher than that of $10.7 million recorded during the comparable quarter of 2007 due to an increase in invested assets.