U.S. residents ended 2007 with $4.7 trillion in individual retirement account assets, up about 12% from the 2006 total.

Researchers at the Employee Benefit Research Institute, Washington have published that figure in an analysis of IRA asset data from a variety of sources.

Life insurers increased their IRA asset total 5.7%, to $336 billion, but the percentage of total IRA assets that they managed fell to 7%, from 8%, the EBRI researchers report.

Mutual funds and brokers selling self-directed IRA accounts increased the amount of IRA assets they managed 13%, to $4 trillion.