Coming to a 401(k) statement near you: investment advice.

A little-noticed provision of the new pension law requires that traditional 401(k) account statements include advice about the desirability of diversifying your portfolio and avoiding loading up on your company's stock.

Employers and financial providers also will have to send 401(k) statements to employees quarterly, rather than annually, as some companies had done.

The new rules fuel a burgeoning trend toward providing investment advice for 401(k) plans. The pension law also has made it simpler for companies — if they choose — to automatically enroll workers in 401(k)s and offer them guidance about where to invest.

The changes come as more employers are adopting 401(k) plans and shifting the responsibility of retirement saving to workers. In 2005, 36 percent of the largest U.S. firms offered no traditional pension, only a 401(k) plan, vs. 10 percent in 1985, according to Watson Wyatt, a benefits consultant.

"The new 401(k) statements provide in-your-face investment guidance," says Suzanne Samuelson of Mercer Human Resource Consulting. "For the first time ... (employers) are putting this information in the one thing that employees read" to track their account's growth.

Companies have often hesitated to offer employees any investment guidance for fear of being sued if the investments sour. Yet too many employees don't participate in their 401(k) plan, and when they do, invest too little.

The pension overhaul gave companies a green light to automatically enroll workers in retirement plans, pre-empting some state restrictions on doing so. The law also allows financial firms that use an asset-allocation model reviewed by a third party to make investment recommendations.

Putting investment advice on 401(k) statements gives savers another push to focus "not just on what they're putting away but how to make this money work for them," Samuelson says.

Employees can expect some form of this warning on 401(k) statements: Don't put more than 20 percent of retirement savings in one company or industry.

The collapse of Enron wiped out thousands of workers' retirement savings and provided millions of others with a stark lesson in the importance of diversification.