WASHINGTON (AP) - Companies selling 401(k) services should be forced to disclose all the fees and expenses that can drain money from workers' retirement plans in writing before businesses trust them with their employees' money, the Bush administration proposed Wednesday.

The Labor Department's proposed regulation is meant to "foster fair, competitive and transparent prices for services as well as combat excessive or hidden plan fees," said Labor Secretary Elaine Chao.

Under the proposed regulation, companies offering 401(k) and other employee benefit plans would have to submit in writing all services their plan offers and all direct and indirect compensation they get from the plan. Plan providers would also have to disclose any possible conflicts of interest that could affect the plan's performance. The proposed regulation would also give protection to employers when plan providers don't complete disclose required information.

"This is going to make a significant difference in ensuring that fiduciaries get the information they need to best serve the interests of workers and to comply with their duties under the law," said Bradford Campbell, assistant secretary for the Labor Department's Employee Benefits Security Administration.

It usually takes anywhere from six to nine months before a proposed regulation becomes final, officials said. The department will first take public comments on the regulation and then can make changes based on the comments. The proposed regulations must also be reviewed by the White House.

With 401(k) plans, employees can make tax-deferred contributions from their salaries to investment accounts. These plans have grown in popularity over the years, while traditional employer-paid pensions that guarantee a monthly benefit have waned.

About 80 percent of investors in 401(k) plans do not know how much fees are eroding their account balances, according to a Government Accountability Office report released last year. Lawmakers, who also have been holding hearings on 401(k) fees, have said a 1 percentage point difference in fees can reduce retirement benefits by nearly 20 percent.

Rep. George Miller, D-Calif., who is chair of the House Education and Labor Committee, called the proposed rule "inadequate" because companies aren't required to disclose fees to workers, only employers. "The department has yet to offer real fee disclosure rules that would be useful to workers trying to plan for their retirement," Miller said.

The Labor Department said the new regulation could cost as much as $52 million in its first year and fall from there, as companies offering 401(k)s and similar services create and disclosure new information.

But the benefits could include plan fees that are lower and reduced costs for businesses trying to find the best deal for their employees, officials said.