Forty-five alleged Communist guerrillas and 3,000 alleged sympathizers surrendered to the government today in a public ceremony organized by the government.

The Philippine Air Force flew foreign correspondents from Manila, 450 miles north of this capital of Zamboanga del Norte Province, to witness the event.

Analysts and diplomatic observers said they do not take these types of events as a measure of the strength of the Communist insurgency or of the Philippine armed forces. More likely, they said, the event was organized to buttress recent assertions by President Ferdinand Marcos that the rebels were "surrendering in droves" and to convince the United States that he is able to contain the insurgency.

The rebels, including 10 women, turned over weapons that included Browning automatics, carbines, shotguns and rusty pistols. Other paraphernalia associated with the Communist New People's Army that was put on public display included notebooks on fighting strategy, knapsacks, binoculars and two ballot boxes said to have been taken from previous elections.

The rebels officially surrendered to the government while the sympathizers, who came from seven nearby municipalities and who allegedly gave food, money and comfort to the guerrillas, raised their hands to pledge their allegiance to the Marcos government in front of the town hall in Polanco, a few minutes' drive from Dipolog.

Polanco is in the center of the province, where the rebels have a large presence. The ceremony was preceded by a band playing Elvis Presley's song, "It's Now or Never." The sympathizers carried placards reading "Let's Fight the NPA." Others urged the military to stay on to eradicate the Communists.

Zamboanga del Norte Province is one of the trouble spots on the island of Mindanao in the southern Philippines. The guerrillas are engaging more than 35 battalions of the Philippine armed forces in Mindanao alone.

According to provincial leaders in Dipolog, the armed forces are having more success against the rebels in recent weeks because of reinforcements from a fighting unit known as Task Force Cobra that has been brought in to counter the insurgency.

Two previous allegiance ceremonies in October involved 1,200 guerrilla supporters, they said. Task Force Cobra's strength has been boosted to four battalions since an Oct. 3 rebel ambush killed 21 soldiers, one of the highest single tolls suffered by the Philippine military in its war in the countryside.

Gen. Fidel Ramos, acting chief of staff of the Philippine armed forces, recently gave a higher estimate of the strength of the insurgency, putting the number of guerrillas at 12,500 instead of earlier estimates of about 10,000.

The governor of Zamboanga del Norte, Alberto Ubay, credited the presence of the military for the success in winning over the guerrillas and sympathizers.

Local officials said repressive taxes imposed on the peasants by the guerrillas led to the switch in allegiance.