NEW YORK — Mortgage giants Fannie Mae and Freddie Mac agreed to take steps to combat inflated home appraisals, but critics doubted the changes would do much good.

In an agreement yesterday with New York Attorney General Andrew Cuomo, the companies said they would buy home loans only from lenders that follow rules specifying how home appraisals can be conducted.

The goal is to force lenders to obtain appraisals from independent experts who give objective and accurate valuations.

Though appraisers are supposed to be unbiased, critics say they are pressured to inflate valuations by mortgage brokers and lenders who collect fees based on the value of loans they make. Overstated home values contributed to the run-up in prices during this decade's nationwide housing bubble, critics say.

"Today's agreement with Fannie Mae and Freddie Mac begins to set right what had gone so horribly wrong in the mortgage industry — rampant appraisal fraud," Cuomo said.

Some appraisers, however, said the new rules, which take effect Jan. 1, won't likely solve the problem.

Banks will continue to put unspoken pressure on appraisers to value homes at desired levels, said Bill King, owner of ValueOne Appraisal in Federal Way, Wash.

"It's going to be a long time before the fundamental way business gets done gets changed."