WASHINGTON (AP) _ More than half of the financial institutions surveyed by a consumer group reserve the right to make changes in home equity loan terms, including raising the interest rate and demanding immediate repayment.

The Consumers Union, the publisher of Consumer Reports, surveyed 45 institutions: 10 major banks and five major savings and loan institutions in each of three metropolitan areas - Washington, New York and San Francisco.

The group, which is pushing Congress to enact legislation barring institutions from making unilateral changes in home equity loans, said 62 percent of the institutions responding to its survey reserved the right to make such changes.

All of the lenders used variable interest rates, the group said. Although the law requires caps on the interest, 58 percent of the institutions set caps at more than six percentage points above the initial rate or higher than 17 percentage points.

Consumers Union said 18 percent of the institutions permit the loans to end in balloon payments and 36 percent permit near-perpetual indebtedness with the minimum loan payment retiring little or none of the principal.

The Senate passed a home equity bill in March as part of broader legislation permitting banks to enter the securities business. The House passed a similar bill in June. The consumer group called on Congress to resolve the differences between the two versions and send the legislation to the White House for the president's signature.

The popularity of home equity loans has soared since passage of the 1986 tax law, which is phasing out the deductibility of interest on most consumer debt except mortgages and other loans secured on a borrower's home.

The Federal Reserve Board estimated in July that three million homeowners had taken out equity loans totaling $75 billion.