Marc Stern's letter {June 5} in support of legislation to close the PLO U.N. Mission to the United Nations and the PLO Information Office in Washington rests on two arguments that, on close examination, cannot be sustained.

First, he argues that closing the PLO offices would not infringe on free speech but would regulate "conduct." He asserts that the PLO would still be able to distribute information and Americans would still be able to endorse or have contacts with the PLO.

The conduct which Mr. Stern wishes to eliminate is PLO informational, diplomatic and political activity; he does not even allege that these offices are engaged in any other "conduct." But the First Amendment right of free speech and assembly, the applicability of which is for citizens and non-citizens alike, protects more than the distribution of literature. Freedom of speech is politically meaningless unless the organizational and institutional means of exercising political expression are protected as well. The right to an office, a mailing address, a staff to produce literature and answer queries, and a phone listing are necessary tools in the exercise of free speech and political expression.

In addition, the legislation under consideration would make it illegal for American citizens to "receive funds" from the PLO. Presumably it would be illegal for Americans to print literature, sell office supplies or provide telephone services to the PLO or serve as its employees. Related legislation would subject anyone to fines or imprisonment or both who "aids, abets, provides services or funds to or accepts funds from, represents, or acts at the direction or behest" of the PLO. So much for the First Amendment and even the right to distribute information.

Second, Mr. Stern argues arrogantly that the "political prestige" of an office and the "important political right" to an official presence in the United States should be conditional on PLO renunciation of terrorism. He chooses to ignore the fact that, while some elements within the PLO admittedly have engaged in terrorist acts, the elected chairman of the PLO Executive Committee, Yasser Arafat, has repeatedly condemned acts of terrorism. Moreover, the staff of the PLO offices in the United States has never been accused of any crime or act of violence.

The PLO is not a terrorist organization and has never been classified as such by either the State Department or the FBI. The PLO is a complex and diverse umbrella organization comprising all elements of Palestinian society. It is the expression of Palestinian nationhood and is, according to polls of Palestinians, universally recognized as their sole legitimate representative. It is in effect a government in exile, and, in addition to military forces, it consists of organizations representing professionals, trade unionists, women, students and other groups that democratically elect the Palestine National Council, a parliamentary body, which in turn elects the PLO Executive Committee.

The attempt to close PLO offices, which was made a top priority at the recent convention of the American Israel Public Affairs Committee, is another attempt by the Israeli lobby to assault the First Amendment and to block Palestinian voices and views from being heard by Americans. The Israeli government has made it a criminal offense for Israeli citizens to meet with the PLO and is prosecuting four Jewish Israelis for meeting with PLO representatives to discuss ways to peace at a public symposium in Romania. These actions, being pushed now in the United States as we approach an election, are an attempt to delegitimize the PLO during the ongoing debate over its inclusion in an international peace conference. ABDEEN JABARA President American-Arab Anti-Discrimination Committee Washington