Iran's chief envoy here said today that his country is ready to cooperate in a regional campaign to clean up the massive oil slick now imperiling the Persian Gulf, but would not accept calls for a cease-fire in its 30-month-old war with Iraq to help accomplish this.

Speaking on the eve of two crucial meetings of gulf environment officials called to discuss the problem, Iranian Ambassador Ali Shams Ardakani said Iran believed a formal cease-fire was not necessary to allow a waiting American company to travel to its Nowruz offshore oil field to repair and cap four leaking oil wells damaged in recent Iraqi attacks.

"We don't need a cease-fire," he said in an interview. Nowruz "is not a battlefield. We didn't initiate any conflict in that area."

The Iranian envoy's comments underline what is reported to be the main Iranian concern about the oil spillage, namely that Iraq hopes to use it to force Iran under international pressure into accepting at least a limited cease-fire around Nowruz that subsequently could be parlayed into a general one serving to halt hostilities between the two warring nations.

The problem of obtaining guarantees from the two warring nations, particularly Iraq, has for a month kept the Texas-based Red Adair Oil Well Fire and Blowout Co. from going to Nowruz to halt the largest spill ever in the gulf.

The slick, now covering 7,500 square miles of gulf waters, has become a serious threat to water desalination plants on the Arab side of the gulf, and there is mounting concern about its effect on shipping.

The damaged wells are spewing forth between 2,500 and 15,000 barrels a day.

The Arab states most threatened--Bahrain, the United Arab Emirates, Qatar and Kuwait--have begun placing booms and other barriers along their shores to protect desalination plants and other vital installations.

In Bahrain, officials were warning that some plants might have to be shut down temporarily to ensure that the oil did not damage them.

There was also mounting concern today about the effect of the tar-like oil slick on water intakes of oil tankers and other ships and fears that it might jeopardize shipping throughout the gulf.

Western diplomats said here the slick could partially obstruct the narrow Strait of Hormuz at the mouth of the gulf because of the slick's size, thickness and the circular flow of water inside the gulf. The slick is reported to be as much as four feet deep at some points.

Officials in Qatar, the small sheikdom located on a peninsula jutting out from Saudi Arabia, were quoted here as describing the situation there as "grave and grim" as its 240,000 inhabitants rushed to stock up on mineral water.

So far, the main body of the slick has not hit any shore because of favorable winds over the last three days. But large detached pieces have been sighted close to both Bahrain and Qatar.

Monday, environmental specialists from all eight gulf states, including both Iran and Iraq, are to hold a meeting in Bahrain to discuss a joint antipollution campaign.

The Bahrain meeting will also prepare for an emergency session of the recently created Regional Organization for the Protection of Marine Environment at a ministerial level here in Kuwait Wednesday.

The main issue facing the organization is how to get an agreement between Iraq and Iran to allow specialists to go to Nowruz to put out fires raging on two oil platforms ever since March 2 and to cap these and two other leaking wells.

Adarkani said the Nowruz field had been closed at the start of the Iranian-Iraqi war because it contained extremely heavy crude of "marginal" value.

He accused Iraq of making a deliberate hit on the oil field and said eight persons had drowned there on March 2 when the Iraqis carried out a second attack.

"They hit the oil field deliberately to create a slick," Ardarkani said. "There was an understanding nobody would attack the oil wells," he added.

"We don't need a cease-fire," he said repeatedly, indicating that Iran regarded it as sufficient if Iraqi President Saddam Hussein declared his own unilateral halt to hostilities against the offshore oil field and gave technicians the necessary guarantees.