WASHINGTON — Making coins may soon make more cents.

Because of rapidly rising metals prices, it currently costs far more for the U.S. Mint to manufacture pennies and nickels than the face value of the coins themselves. So taxpayers lose money in the making of the coins.

But a measure recently proposed by members of the Senate and House would allow the mint to alter the metal composition of coins to make them cheaper. Currently, only Congress can change coin compositions, which happens only rarely.

"We should make the government more efficient in any way we can," House Financial Services Committee chairman Barney Frank, D-Mass., says of the measure.

The committee says a change in the composition of the penny and nickel could save the government more than $100 million each year. Changes to higher-denomination coins could raise the savings to $400 million.

It currently costs approximately 1.5 cents to produce a penny and 8.2 cents to produce a nickel, according to the mint. Skyrocketing metal prices are a result of a strong worldwide economy. For example, copper costs are up more than 24 percent since the start of the year.

The higher metal costs led the mint earlier this year to prohibit people from melting down coins to sell the metal, out of concern that a coin shortage could evolve. Violators face five years in jail. So far, no one has been caught breaking that law.

The mint makes up for the losses of producing pennies and nickels with higher-value coins such as quarters. But the head of the mint said he would welcome the opportunity to cut costs.

The penny has been 97.5 percent zinc and 2.5 percent copper since 1982. The nickel has been 75 percent copper and 25 percent nickel since it was first produced in 1866 except for a brief period during World War II.

Altering the coins would need to be done carefully, notes Rod Gillis, of the American Numismatic Association. Metals vary in weight and hardness and changes can make a difference in the manufacturing process.

Plus, vending machines recognize the value of coins in part by the electromagnetic signature that is unique to the composition of the metals.