Iraq is buying 45 American-made civilian helicopters initially developed as Iranian troop carriers in a $200 million deal that has raised questions by some U.S. officials about a possible breach of the Reagan administration's arms embargo in the five-year-old Persian Gulf war.

The magnitude of the sale -- and potential military use of the aircraft -- also appears to tilt the United States further toward Baghdad despite Washington's official neutrality in the conflict.

A spokesman for Bell Helicopter Textron of Fort Worth, the manufacturer of the 20-seat 214 Super Transport helicopter, said the first craft was delivered to the Iraqi Communications and Transport Ministry in July. Several more are expected to be shipped before the end of this year.

One U.S. official monitoring the transaction said the helicopter was "clearly a dual-use item" with "a potential for military use." But because it is now certified as a civilian aircraft by the Federal Aviation Administration, he added, it does not require a special license under the provisions of the Arms Export Control Act or formal congressional approval.

The Bell spokesman, Marty Reisch, said his company had nonetheless kept the State and Commerce departments informed during the long negotiations with Iraq.

Congressional sources said the sale had raised some concern within Commerce and Defense because of the military potential and the fact that U.S. arms export regulations did not cover it.

The same type of helicopter has been sold to oil companies for offshore operations, to the Venezuelan and Peruvian air forces, and to the Royal Thai army, according to the latest edition of Jane's "All the World's Aircraft."

A State Department official said there is no evidence that Iraq is using the big Bell helicopter for military purposes. There is "an understanding" between the two governments that the craft will remain strictly civilian, he added.

Other U.S. government sources said Baghdad had been warned that use of the aircraft was being monitored, and that military use could "severely damage" improving U.S.-Iraqi relations.

Critics in the U.S. government believe the helicopter sale represents a possible breach in the administration's longstanding policy of not selling arms to either side in the Iran-Iraq war. The United States recently tightened up its arms embargo and prosecuted several U.S. citizens on charges of illegally shipping arms to Iran.

Washington has also issued repeated denunciations of Iraq's use of chemical weapons in the war.

Nevertheless, the administration has shown an increasing tilt toward Iraq in the war by seeking improved diplomatic and trade relations with the Baghdad government since restoring formal ties in November 1984 after a 17-year break.

After months of delay, a U.S. inter-agency delegation led by Commerce Department officials is leaving for Iraq in the next few weeks to negotiate what is described as an "umbrella" government-to-government commercial agreement. The Iraqis also have sought financial credits to buy U.S. goods and a joint economic commission, such as the United States has with Saudi Arabia and several other Arab countries.

Iraq had been involved in periodic negotiations to buy the sophisticated Bell 214ST for almost two years. Press reports earlier this year said Baghdad had reached a preliminary agreement with Bell last December to buy 45 helicopters designated for the Ministry of Agriculture.

The Bell spokesman said subsequent deliveries of the $4 million to $5 million helicopters will be made later this year "if the funding is available." Because of dwindling oil exports and the war's high cost, Iraq has run up at least a $40 billion foreign debt and suffered an acute cash shortage.

The total value of the deal has not been disclosed but various press reports estimated the sale at $225 million to $275 million, including spare parts. Iraq has also recently spent $25 million to buy 24 530F five-seat helicopters from the Hughes Aircraft Co.

The 214ST transport helicopter has an unusual history. A first model, the 214A, was developed in the early 1970s by Bell for the Iranian army as a transport aircraft. The first prototype flew in early 1977.

Subsequently, Bell developed what a spokesman described as a larger and more powerful version with a multipurpose capability. It was certified by the FAA in 1982 for commercial sale.

The Bell spokesman said the later 214ST model was primarily designed for use by oil companies in offshore operations and that 40 to 45 of them have been sold for that purpose.