U.S. companies are sitting on a nice pile of cash these days, with more than $1.8 trillion on their books. But corporate America also has a Mount Everest of debt, a record $7.2 trillion. Too much debt, of course, can crush profits, and an increase in interest rates can make payments on that debt more expensive. That's why some investment pros are placing their bets on firms that not only have a stash of cash but also a dearth of debt.

Many economists believe higher interest rates aren't coming until next year, given the economy's shaky state. But some pros are getting ready now for a rate hike later. When rates rise, companies with relatively low levels of debt typically outperform firms with more leveraged balance sheets, says Russ Koesterich, head of investment strategy for scientific equities at BlackRock. Technology, energy and health care firms often have manageable debt levels and typically fare best, he adds, while utilities-which tend to have heavier debt loads-usually lag.

Companies with low debt also have more flexibility to use their cash for share buybacks or dividend increases, notes Eric Ende, comanager of the FPA Perennial fund. "Leverage can be really unpleasant when it doesn't work," Ende says. And when rates rise, low-debt companies will be able to expand their businesses at the expense of their indebted rivals. For example, Varian Medical Systems, which makes radiation machines to treat cancer, has hardly any debt. So higher interest rates won't take a bite out of profits, and the company can focus on expanding its 60 percent global market share.

Investors are already rethinking their exposure to risk-especially with the market's recent volatility, says Koesterich. He figures higher-quality, low-debt companies will take the lead when rate hikes get closer to becoming a reality. Of course, firms with low debt can still be duds if they aren't growing their businesses. And in a slow-growth environment where the economic pie isn't expanding, the best bets might be stocks that have the dual advantage of low debt and growing market share, such as Apple (AAPL) and electronics retailer hhgregg, says Samuel Dedio, a fund manager with Artio Global Investors.

Hold the Debt, Please

With clean balance sheets, these firms could do well even if rates rise.

C.H. Robinson Worldwide (CHRW)
This provider of transport and logistics services can expand and contract with the economy and still maintain profit margins, says Robert McIver, comanager of the Jensen Portfolio fund.

Varian Medical Systems (VAR)
The company, which makes radiation machines to treat cancer, generates high returns on capital and has good growth prospects, says Ende.

Hhgregg (HGG)
This smaller rival of Best Buy is opening stores at a rapid clip. Its debt is also "quite manageable," says Dedio.