The decision to transfer billions of dollars in bank deposits and gold to Iran in return for the release of the 52 American hostages is requiring some of the most complex diplomatic and commercial negotiations in peacetime history.

But the transfer itself will be nearly as simple as writing a check or pushing a button.

Unless Iranian officials require the United States to create $5 billion in unmarked bills for Tehran, the denouncement of the hostage crisis will involve nothing more than the mundane international transfers of money by cable that banks do thousands of times each business day.

No bills will change hands. Only the banking equivalent of telegrams will note the transfer of billions of dollars from the books of banks like Citibank, Chase Manhattan or Continental Illinois to the central bank in Iran. Bankers are standing by -- because normally banks are closed over the weekend -- to give the Federal Reserve Bank of New York the authority to transfer funds if an agreement is reached. The Federal Reserve also has officers on duty this weekend.

The Treasury Department, with the assistance of England, already has eased the way for transfer of the 1.632 million ounces (51 tons) of Iranian gold stored in the vaults beneath the Federal Reserve Bank in lower Manhattan. It is likely that not an ounce of gold will leave the United States.The switch involves more than changing ownership labels on gold stored at government facilities in New York, London and, perhaps, Tehran.

Much of the gold owned by foreign governments is stored in the Manhattan bank's massive vault. Each country has a cage. If England wants to transfer gold to, say, the Netherlands, it can wire the New York Fed instructions and the Fed takes the gold out of England's cage and and puts it in the Netherlands' cage. The Fed, however, does not store U.S. gold, so the Treasury had to use gold it has stored in a facility at its assay office in Manhattan.

In the assay office Friday, the Treasury set aside 1.632 million ounces of gold (worth about $930 million) for England. In London, the Bank of England took 1.632 million ounces of its own gold and labeled it U.S. gold.

When the hostage accord is reached, the United States will direct the Bank of England to put an Iranian ownership label on that gold. The Treasury would then direct the Federal Reserve in New York to take the 1.632 million ounces of gold out of Iran's cage and put it into England's, leaving Iran's cage empty. The gold at the assay office, labeled England's, would then become U.S. gold again.

When the Federal Reserve transfers the $1.5 billion of Iranian assets it owns and the banks send the billions of deposits back to Tehran, real wealth will leave the United States, but in the form of electronic impulses.

The most likely scenario, according to federal and banking officials, is that banks, which maintain their own accounts with the Federal Reserve, will direct the U.S. central bank to take funds out of its account and wire instructions to Tehran to add the equivalent amount of funds to the Iranian central bank's account.

Officials expect that the Federal Reserve, which serves as the official international bank for the U.S. government, probably will collect the deposits from the dozen or so U.S. banks with Iranian accounts and complete the transaction with one telegram (through a long-established international banking wire hookup), although each bank could do it individually if Tehran prefers it that way.

The net effect is the same as when an individual writes a check to another. The recipient's bank adds funds to its customer's account and the check-writer's bank deducts the same amount of funds from the checking account. cThe only difference is the customers are the United States and Iran.