A SPECIAL MONDAY REPORT ON YOU AND YOUR MONEY;Because of the explosive growth of 401(k) retirement plans, millions of workers are becoming their own retirement fund managers. It's a daunting responsiblity. Here's a special report to help you manage your 401(k) portfolio.;See sidebar:Guaranteed contracts contain some risks

Many 401(k) plans let employees invest in their company's stock. Think carefully before choosing that option. ``You've got so much of your life tied up in your company,'' says Ernst & Young's Victoria Alther. ``You probably want to leave it out of your 401(k).'' It's easy for investors to fall in love with a company, and then have trouble bringing themselves to sell when it's stock is doing badly. That problem is compounded if you are working for the company.

Coordinate: What you do with your 401(k) should also fit in with how you're investing your other money. If you already have a lot of stock holdings, a 401(k) can be the ideal place to keep investments that generate lots of income. Let your interest-earning and high-dividend-paying investments grow inside your 401(k) - tax deferred. Let your price- appreciation stocks grow outside, because that growth isn't taxed until you cash them. Also, you can claim tax deductions for losses on stocks outside a 401(k). You get no tax breaks for losses on investments held inside them.