U.S. life insurers’ direct premium revenue increased to $657 billion in 2007, up 10% from the 2006 total.

Researchers at Highline Data, Cambridge, Mass., a unit of Summit Business Media L.L.C., New York, have published those figures in a summary of data drawn from the company’s latest 2007 life insurance industry data update.

Preliminary 2007 totals are available through Insurance Analyst PRO, a Web-based database that includes detailed statutory financial data from all available blanks.

The database now includes information from 857 companies, or about 92% of all life insurance companies that are expected to file 2007 blanks and 98 of the top 100 filers, according to Highline Data, which is a sister company of The National Underwriter Company, the publisher of the NU Online News Service.

Direct premium revenue grew 16% for individual life insurance products, 9.1% for individual annuities, and 3.9% for group annuities.

Total admitted assets increased 5.8%, to about $5 trillion, and only 23 companies reported a decrease in total admitted assets.

But unconsolidated net gains from operations fell 9.7%, to $37 billion, and the average risk-based capital ratio has fallen to 805%, from 816%.

Only 8 companies have reported an RBC ratio below 200%, Highline Data researchers note.

The 2007 filings “reveal that life insurers managed to sidestep the subprime credit debacle and come through 2007 in good shape,” says F. Reilly Cobb, managing director of Highline Data. “Still, the stock market tumble in the fourth quarter has taken a toll on many securities portfolios. First-quarter filings will be the key to understanding how insurers have managed the market’s impact as they move into 2008.”