With little fanfare, the first tanker-load of crude oil from the new, 589-mile Iraq-Turkey pipeline recently left the Mediterranean port.

It was an event of major economic and political significance for both countries.

The $850 million, 40-inch pipeline, one of the longest and most modern in the world, provides Iraq with a new export outlet to the Mediterranean and insures developing Turkey of more than half its oil requirements at reduced cost.

It helps cement recently-improved relations between Ankara and Baghdad, and makes Iraqi oil more competitive on southern European markets because of reduced transport costs.

It also reduces Iraq's dependence on Iranian and Saudi Arabian-controlled Persian Gulf ports, which have been Iraq's sole export outlet since the closing two years ago of an Iraq-Syria pipeline to the Mediterranean because of political differences between the two countries.

The new pipeline runs from Iraq's oil-rich Kirkuk Province, across the Tigris river, over the rugged mountains of eastern Turkey to the terminal here at the northeast corner of the Mediterranean. It was built at the suggestion of Iraq by the Turkish and Iraqi national oil companies and is operated by their subsidiaries.

Each country paid for construction of its section of the pipeline - 385 miles in Turkey costing $600 million and 204 miles in Iraq costing $250 million. Turkey got financial help from European and Middle Eastern sources for its share.

The actual construction work was done by companies from the United States, France, West Germany, Italy and The Netherlands, as well as Turkish and Iraqi companies. Pipeline was purchased from Italy, West Germany, France and Japan.

The project took only two years to complete, the fast finish due in part, officials said, to the use of a new automatic pipe-welding technique developed in the United States.

The pipeline was ready for operation last January but pumping was delayed three months by haggling between Ankara and Baghdad over the price Turkey should pay for oil. The agreed price is a closely-kept secret, but officials concede it is below the average for crude oil.

Under the agreement, Turkey has the option to purchase approximately 40 per cent of the pipeline's total annual capacity of 35 million tons. Turkey also expects to earn about $100,000 a year in oil transit fees.

The pipeline's five pumping stations - two in Iraq and three in Turkey - are controlled from computer centers in Ceyhan and Kirkuk.

The line is presently operating at about two-thirds of its total capacity, but officials hope to have it operating at full capacity sometime next year. Storage facilities at Ceyhan include seven tanks bigger than football fields.

The loading dock here is the longest in the Mediterranean and can handle tankers of up to 300,000 deadweight tons at the rate of 20,000 tons of oil an hour.