Net U.S. life operating gains fell to $27.4 billion in 2006, down from $32.8 billion in net operating gains in 2005.

Analysts at Conning Research & Consulting Inc., Hartford, have reported those figures in their latest industry performance review.

Under U.S. Generally Accepted Accounting Principles, total industry net operating income totaled about $61 billion, Conning analysts estimate.

Net operating gains could increase in 2007, 2008 and 2009 as individual life sales improve and group annuities stabilize, according to Stephan Christiansen, Conning’s research director.

The industry’s shift toward stock-based variable products has been helping profit margins, and that could lead to 7.3% compound annual growth in net premiums from now through 2009, Conning analysts predict.