Iraq has rejected a U.S. plea that it stop renewed attacks on Iranian oil facilities in the Persian Gulf, telling the Reagan administration that it regards the request as "regrettable and astonishing," diplomatic sources said yesterday.

The formal Iraqi rejection was communicated Sunday in Baghdad to U.S. Ambassador David Newton after Assistant Secretary of State Richard W. Murphy had sought a halt to the raids when he met here Saturday with Iraqi Ambassador Nizar Hamdoon, the sources said.

The sources said Iraq, in explaining the rejection, cited what Baghdad regards as authoritative Iranian statements that Iran will not accept the U.N. Security Council resolution July 20 demanding a halt to fighting in the seven-year gulf war.

Iraq reportedly told the administration that it waited 45 days before resuming its raids, finally deciding that Iran had no intention of accepting a cease-fire in the land war despite its refusal to reject the U.N. resolution formally.

The sources said Iraq feels that escalating tension in the gulf may be the best way to increase international pressure on Iran to end the conflict.

Iraq had agreed quickly to the U.N. cease-fire resolution but warned that it would not accept a halt to gulf hostilities alone.

Iraq's rejection of a continued cease-fire in the gulf "tanker war" was also made known in a letter Saturday from Foreign Minister Tariq Aziz to U.N. Secretary General Javier Perez de Cuellar.

"Any calls for a halt to attacks on those {Iranian gulf} interests translate, in practical terms, into service of the war effort of Iranian aggression against Iraq and the countries of the region," Aziz said.

The renewed Iraqi air attacks on Iranian tankers and other gulf oil facilities, which continued for a third consecutive day yesterday, appear to have surprised the administration.

The raids have put a new strain on relations between Baghdad and Washington, which had recently stepped up diplomatic efforts to force Iran to end the war.

In Santa Barbara, Calif., yesterday, White House spokesman Marlin Fitzwater declined to say whether the United States is providing Iraq with intelligence information that has enabled it to bomb Iranian oil-producing facilities even in the gulf's southernmost area.

Senior administration officials there said the United States is not providing military intelligence

to Iraq, as it had done secretly ear- lier.

State Department spokeswoman Phyllis Oakley yesterday repeated comments by Undersecretary of State Michael H. Armacost Sunday that the timing of the renewed Iraqi attacks was "deplorable," "unfortunate" and "regrettable."

Oakley indirectly confirmed reports that the United States has asked Iraq to halt the raids, saying the department has made Hamdoon aware of "our deep concerns on this issue."

She also indicated that the United States differs with Iraq about whether Iran has effectively

rejected the cease-fire call and

said the United States believes

that Tehran may accept the resolution or agree to discuss it further.

Oakley noted that Iranian Deputy Foreign Minister Mohammed Larijani, or another Iranian diplomat, is expected this week in New York for more discussions with U.N. officials on the resolution.

"We certainly hope that there will be a favorable response from Iran," she said.

"We have not put a time limit in any way on" an Iranian response, Oakley said, adding that the Iraqi attacks last weekend "make it even more imperative to move in the Security Council to enforcement measures."

The United States has begun discussions with other permanent Security Council members, including the Soviet Union, about poten- tial support for a second resolution imposing an arms embargo on Iran for refusing to accept a cease- fire.

Senior administration officials in Santa Barbara said they believe that Iran's willingness to accept a cease-fire will depend on its perception of progress at the United Nations toward implementation of such sanctions.

One official suggested that Iran might move to preempt the impact of a U.N.-imposed arms embargo and accept the cease-fire if it fears that such sanctions are likely to be approved.