Iran's offer to use its influence to free American hostages in Lebanon - if the U.S. will return Iranian assets frozen in this country since 1979 - was quickly and correctly turned down last week by the Reagan administration.

The U.S. is going to stand fast on its "no deal" policy when it comes to the hostages. That is understandable after the administration was badly burned in the arms-for-hostages attempt that turned into the Iran-Contra scandal.The refusal to make deals for hostages, to pay ransom or blackmail, or anything like it, always was a sensible policy and should never have been ignored in the first place - as the administration is admitting with its latest rejection.

There is nothing wrong with releasing Iranian assets, although there are legal questions still to be resolved. But any such step should await the normalization of relations between the U.S. and Iran, and definitely should not be part of a hostage deal.

In the first place, there is no guarantee Iran could win the hostages' release, even though the kidnappers apparently belong to a pro-Iranian terrorist group. Iranian officials said earlier that they have no control over the kidnappers. Either they were lying then or they are lying now.

Offers to intercede have been made quietly by Iran before, but always in exchange for something. That amounts to Iran joining hands with the kidnappers and releasing the hostages in return for a payoff. That amounts to rewarding the hostage-takers. That, in turn, makes hostage-taking profitable and puts innocent people everywhere in greater danger.

Iran has about $1 billion in a military sales escrow account set up in the U.S. by the late Shah for purchase of military equipment. The equipment was never delivered after Iran seized hostages at the American embassy in Tehran.

Another $1.5 billion is in a special bank account which is at the center of arbitration by the U.S.-Iran Claims Tribunal, established at the time the embassy people were released after 444 days in captivity.

The tribunal so far has awarded American claimants about $1 billion and Iranian claimants about $60 million. U.S. officials say that individual claims and the interest payments will not be rejected, but refuse to link any financial question with the hostages.

The U.S. is willing to move toward normalizing relations with Iran. That's something it would do if no hostages had ever been taken. But there can be no payoffs as a condition for getting the hostages out.