With promises of aid and arms for Sudan and a network of sympathetic Sudanese Revolutionary Committees operating here, Libyan leader Muammar Qaddafi has moved quickly to establish a high profile in Khartoum since the overthrow of president Jafaar Nimeri in April.

Thus far, though, little of Qaddafi's promised largess has been seen in this food-short country. And the Revolutionary Committees, potentially the most troublesome for Sudan in its current western orientation, have yet to find political roots. Various well-informed analysts suggest there is more show than substance in the Libyan presence, at least for now.

"Qaddafi is always trying to take over someone else's country," Libya's exiled former prime minister Abdulhamid M. Backoush said recently in Cairo. "But nothing will work between the Sudan and Libya, that's for sure. Qaddafi will do something to make them angry the way he has with everyone else."

Leaders of the new government here seem surprised by concerns that their new relations with Libya have raised in Washington and Cairo, where Qaddafi's government is regarded virtually as an outlaw fostering international terrorism.

"There is nothing in our relations with Libya, or with any other country for that matter, which calls for alarm in either Egypt or the United States," Gen. Abdel Rahman Sawar- Dhabab, leader of the Transitional Military Council, said today in a written response to questions.

Sawar-Dhabab noted that Libya has "offered to supply us, as a gift, with oil enough to meet our needs for three months. It has agreed to supply us with transport aircraft to help airlift relief foodstuffs and medicine from Port Sudan to famine stricken areas. For this and other aid we are indeed grateful."

Yet of 1,000 truckloads of supplies for famine victims promised in May, at most 50 are reported to have arrived in western Sudan. The supply of petroleum appears uncertain, and has only belatedly begun, according to diplomatic sources. Four Libyan Air Force planes sent for the relief effort have remained for two months at the Khartoum airport virtually unused, relief officials say, because they are too small.

Referring to a military protocol announced last week by Sudan's defense minister, Sawar-Dhabab said, "The Sudan has concluded no defense pact with Libya. It has only agreed to receive aid for its Air Force and Navy."

Western military analysts suggest that Sudan's main interest in the protocol is the acquisition of free spare parts for aging Soviet-built equipment acquired in the late 1960s and early 1970s.

One western diplomat said of the still unpublished protocol, "We are not sure whether it is a treaty or a pact or a press release. But the more we hear about it, the more it seems likely to be a press release."

A central reason for the Sudanese government's efforts to warm relations with Libya has been its hope that Qaddafi would end support for the rebellion of ex-colonel John Garang in non-Moslem southern Sudan. But while Qaddafi has publicly assured Sudan's leaders several times that he would help end the fighting in the south and would cut off any arms supplies he might have been sending to Garang, the fighting continues.

As this country's problems of famine, civil war and virtual bankruptcy weigh on the loosely structured transitional government, and popular impatience grows, there is obvious potential for Qaddafi and his sympathizers to take advantage of discontent.

Khartoum has seen a new wave of protest marches in recent weeks, including a peaceful protest yesterday by bank employes that police broke up with tear gas and clubs. It was the first time since the overthrow of the Nimeri dictatorship that such force has been used against protesters.

Although there is no solid evidence linking Libya to yesterday's march or other demonstrations, officials in Washington have expressed concern about Libyan agents secretly infiltrating Sudan since Nimeri's state security organization was dismantled. U.S. officials reportedly have increased security here as a precaution against possible Libyan-backed terrorism aimed at Americans.

But much of Qaddafi's effort to gain influence here is conspicuous rather than covert, and many Sudanese seem to consider it arrogant. When Qaddafi arrived at Khartoum airport on May 18, he gave Sudanese officials only a few hours' notice, forcing several top officials suddenly to rearrange their schedules to accommodate him.

Both Qaddafi and his top deputy, Abdul Salaam Jalloud, who visited for a week in May, made disparaging comments about Egypt and the United States that some Sudanese officials regarded as pointlessly insulting and provocative to countries with which Sudan has vital ties.

Qaddafi called for an end to Egyptian influence here, then promised that his "popular revolution would infiltrate artificial borders," according to a report by the official Sudanese news agency.

The Libyan embassy that was shut down by Nimeri -- who once called for Qaddafi's assassination -- has reopened under a tattered green flag as the Libyan Brotherhood Office. The most conspicuous Libyan influence, however, is the headquarters of the Sudanese Revolutionary Committees across the Nile in Omdurman.

The front of the bright green building, which used to be a third-rate motel, is now draped with banners declaring, among other things, "The masses demand the head of Nimeri," who is exiled in Egypt.

The main organizers of the committees are long-time revolutionaries with extensive military training and experience in clandestine operations, according to Sadiq Ibrahim, one of their spokesmen.

Ibrahim said about 1,800 Sudanese exiles have returned under the committees' auspices since the April coup, but he declined to estimate the membership of the committees.

During the Nimeri regime, he said, "We used to keep our work very secret" and as exiles, members of the committee went to "many countries for military training and ideological and psychological courses." Ibrahim was reluctant to name those countries, but mentioned that during his 10-year exile he had been in Syria and Lebanon and had worked with the Palestine Liberation Organization.

Within about three weeks of the coup, the leader of the Sudanese Revolutionary Committees, Abdullah Zakaria, flew to Khartoum with about 200 of his men, Ibrahim said. They arrived uniformed and armed, but turned their weapons over to the authorities here, he added.

"The western and especially the American media try to portray us as terrorists commanded by Qaddafi," Ibrahim said. "Absolutely, we are not like that." Since the group's primary goal had been to oust Nimeri, Ibrahim said, there was no need to keep the weapons.

Western diplomats note that the committee's people could easily rearm if they chose. Ibrahim said that if the committees were to be suppressed by a new government, "of course" its members would again take up weapons.

Using Qaddafi's philosophy of an unstructured peoples' government as its model, the revolutionary committees hope to make Sudan "a progressive country," said Ibrahim.

Mainstream Sudanese politicians trying to rebuild a government and their own parties after 16 years of Nimeri's dictatorship appear to have little patience with any of this.

The Umma Party of Sadiq Mahdi, for instance, received substantial support from Libya when it was being persecuted by Nimeri in the 1970s. During Jalloud's visit here in May, Mahdi held a rally in his honor, to show, as one senior Umma official put it, "a little bit of gratitude."

But asked what he thought of Qaddafi's political ideas, the Umma official dismissed them as useless.