WASHINGTON — The elderly and other vulnerable homeowners are losing their homes because they owe as little as a few hundred dollars in back taxes, according to a report from a consumer group.

Outdated state laws allow big banks and other investors to reap windfall profits by buying the houses for a pittance and reselling them, the National Consumer Law Center said in a report being released Tuesday.

Local governments can seize and sell a home if the owner falls behind on property taxes and fees. The process helps governments make ends meet at a time when low property values and the weak economy are squeezing tax revenue.