Americans flush with cash as they regain equity in their homes are spending more after years of pinching pennies.

The share of owners whose homes are worth at least 50 percent more than they owe on their mortgages rose to 18 percent in the fourth quarter as property prices gained, up from 16 percent in the prior three months, according to a report today by RealtyTrac, an Irvine, Calif.-based real estate data firm. U.S. homeowners held $9.7 trillion of equity in the third quarter, a 4.5 percent gain from the earlier period, according to the Federal Reserve.