BEIRUT, MAY 21 -- Lebanon's parliament today annulled a controversial 1969 agreement that gave freedom of movement to Palestinian armed forces in refugee camps and in southern Lebanon.

Political observers saw a clear Syrian role in the decision, which is expected to limit further the activities of the Palestinian guerrillas, already reeling from a months-long siege by Shiite Amal troops and restricted by Syria's military presence here.

House Speaker Hussein Husseini, a Shiite Moslem, said after the vote that the 1969 accord, known as the Cairo Agreement, had never been properly implemented in letter and spirit and had "cost Lebanon and is still costing it due to the disproportionate expansion of armed and illegal Palestinian presence on Lebanese soil."

The abrogation comes less than a month after the Palestine National Council, the PLO's parliament-in-exile, upheld the agreement in resolutions concluding its latest meeting, held in Algiers last month.

The 46 deputies in Lebanon's parliament also unanimously annulled a U.S.-sponsored agreement that the government of then-prime minister Chafiq Wazzan reached with Israel on May 17, 1983, that provided for mutual recognition by the two states. It also provided for Israeli troop withdrawal, cooperative security arrangements in southern Lebanon and a ban on hostile PLO activities there. It was scrapped the following March, under pressure from Syria.

The Cairo Agreement was signed Nov. 3, 1969, between Palestine Liberation Organization leader Yasser Arafat and the Lebanese Army's commander-in-chief at the time, Emile Boustany, after mediation by Egypt's Gamal Abdel Nasser.

The Palestinian guerrillas had demanded full freedom to operate in Lebanon and carry out attacks against Israel. Lebanese Christians, more powerful then than now, opposed granting the PLO the authority to act as a "state within a state."

Syria imposed a months-long blockade in early 1969 to press the Lebanese leadership into authorizing Palestinians living here to take part in "armed struggle" against Israel and the Cairo Agreement was drawn up as a compromise.

The agreement restricted the guerrillas' freedom of movement to specific areas, but also ensured supply and reinforcement lines through the Arqoub region in southeastern Lebanon. The Arqoub, because of a dense Palestinian guerrilla presence, became known as Fatahland in the early 1970s.

Loose interpretation of the accord and growing Palestinian military strength coincided with Christian-Moslem friction and helped touch off the Lebanese civil war in 1975. The Christian camp opposed the Cairo Agreement from the start and blamed unbridled guerrilla activity in Lebanon for its woes.

Since then, the Shiite Moslem community, the hardest hit by Israeli military action in southern Lebanon, has turned against the Palestinian resistance as well.

Abdellatif Zein, a Shiite deputy from Nabatiyah, in southern Lebanon, welcomed today's vote with a curt: "No more Fatahland." He explained that parliament had never specifically endorsed the Cairo Agreement but had given the government under then-prime minister Rashid Karami a vote of confidence.

Three weeks ago, Karami, who became prime minister again in April 1984 as head of a national unity government, resigned after coming under harsh criticism from the right and the left for allegedly mismanaging government affairs. No successor has been appointed.

Cancellation of the Cairo Agreement has been a standing Christian demand that was seconded by Moslem leaders after Israel invaded Lebanon in 1982. A bitter war between Palestinian guerrillas and the Syrian-backed Shiite Amal, which raged on and off from May 1985 until last April, and hostility between Syria and Arafat have helped set the stage for the scrapping of the accord.

The PLO's military strength was sharply curtailed in the wake of the Israeli invasion, with the departure of about 12,000 guerrillas to other Arab capitals. However, Palestinian guerrillas have returned gradually and in small numbers in the past year. There are an estimated 500,000 Palestinians living in Lebanon, but there is no official breakdown of civilians and fighters, who are said to number several thousand.