Iraqi President Saddam Hussein has replaced the nation's aged defense minister with a younger military officer renowned in his country for directing the successful defense of Basra against an assault by waves of Iranian troops in 1982, state-run Baghdad radio said yesterday.

A broadcast said Maj. Gen. Saadi Tuma Abbas, 51, was appointed to the top defense post from his current job as the military's inspector general. He replaced Gen. Abdel-Jabbar Shanshal, a close associate of Saddam who was shifted to the ceremonial post of state minister for military affairs.

The announcement came as Algerian President Chadli Bendjedid and Foreign Minister Ahmed Ghazali arrived in Baghdad for meetings with Saddam and possible mediation of the crisis, after completing talks in Amman with Jordan's King Hussein.

U.S. government analysts here said they accepted Saddam's statement in a presidential decree released yesterday that Shanshal was retired due to age, reported by news services as 70 and by U.S. officials as 75.

The U.S. analysts said the shift did not appear to be associated with any split within the Iraqi ruling circle over the nation's policy on Kuwait.

"This is part of Saddam's effort to put in {office} guys who are capable of fighting a war," one analyst said. "Abbas is considered experienced in Western concepts of war {including} high mobility, high firepower warfare."

Abbas was the army field commander who directed Iraq's July 1982 battle with Iran near Basra in southeastern Iraq, one of Iraq's critical victories in its eight-year war with Iran. To repel the Iranian attack, the Iraqis made extensive use of defensive fortifications, which slowed the massed assaults by young, poorly trained Iranian troops and subjected them to withering fire by Iraqi artillery and soldiers.

Similar but more elaborate fortifications have been erected by Iraq along the border between Kuwait and Saudi Arabia to slow any advance by U.S. and allied ground troops attempting to oust the occupying Iraqi forces.

In another sign of continuing Iraqi preparation for the possibility of war, the official newspaper of Iraq's ruling Baath Party reported yesterday that owners of buildings with at least two floors had been ordered by civil defense authorities to convert their basements into shelters and post signs outside directing citizens on how to take cover.

The prospects for the Algerian mission to Baghdad remained unclear, according to U.S. officials in Washington. Jordanian officials have said Bendjedid is seeking to revive an Arab diplomatic initiative aimed at bringing together Iraq and Saudi Arabia to discuss a negotiated settlement of the crisis.

Algeria, which has mediated other territorial disputes in the region, so far has followed a course between the positions of Iraq and Saudi Arabia, condemning both Iraq's invasion of Kuwait and the stationing of Western troops on Saudi territory.

In the past, senior U.S. policy-makers have expressed worry that such interventions by foreign leaders eager to broker a deal could open a negotiating "bazaar" with Saddam that would produce only a partial solution.

U.S. officials have said Secretary of State James A. Baker III's expected trip to Baghdad is intended partly to head off other negotiating attempts during the period before expiration of the Jan. 15 U.N. deadline for Iraq's withdrawal.

Diplomats in New York said yesterday that foreign ministers from the five permanent members of the U.N. Security Council would likely meet in Europe later this month to renew their withdrawal demand and offer formal assurance to Saddam that his acceptance will block any military attack, the Associated Press reported.

In other developments, Britain's Foreign Office announced that the last two British diplomats in Kuwait will leave within a week. It also said an estimated 50 British citizens remain in the country after a general evacuation of foreigners earlier this week, including some who had apparently decided to stay behind.

Twenty Irish citizens, three Canadians and two Italians flew to Amman from Baghdad yesterday, while a group of Americans departed for the United States from Frankfurt on the second leg of their trip home from Iraq, the Associated Press reported. A final U.S. evacuation flight from Baghdad is set for today.

Staff writer David Hoffman contributed to this report.