Israeli Prime Minister Menachem Begin today rejected Egyptian President Anwar Sadat's suggestion that the Palestine Liberation Organization be included in a major new effort to bring about a comprehensive Middle East peace settlement.

Referring to an Israeli-Egyptian summit conference tentatively planned for next month, Begin said, "If I meet him in Alexandria, I will tell my friend Anwar, 'I disagree with you completely if you try to bring into the negotiations that murderous organization. . . .'"

Sadat told reporters in Washington yesterday that in his talks with President Reagan and Secretary of State Alexander M. Haig Jr. he had suggested following up the PLO's cease-fire with Israel in Lebanon by U.S. contacts with the organization. Haig then said he rejected the suggestion.

Begin, citing the longstanding U.S. commitment to Israel not to negotiate with the PLO until it recognizes Israel's right to exist, said of Sadat, "He actually asked the United States to recognize the organization which calls itself the PLO. I do not object to the 'P,' neither the 'O.' I have deep objection to the 'L.' It stands for liberation. This is not a liberation organization. It is in the most total sense of the word a terrorist, killers' organization."

Referring to Farouk Khaddoumi, the PLO's foreign minister-in-exile, who was quoted as saying that the PLO would never recognize Israel, Begin declared:

"Every Israeli should know that behind him stands, as he put it, a guerrilla, and he is out to get us. . . . Of course, I cannot agree on this issue with my friend Anwar."

[The Associated Press quoted Begin as also charging that Saudi Arabia supplied weapons to the PLO. He did not elaborate, The AP said, but the newspaper Maariv said the weapons were U.S.-made, and quoted informed sources as saying the Saudis were also shipping American arms to Iraq.]

Begin added that he did not object to negotiations "with our Arab neighbors, who are called Palestinians, but not, under no circumstances whatsoever, with the so-called PLO."

The prime minister added in an interview on Israeli radio that he expects the negotiations for proposed autonomy for West Bank and Gaza Strip Palestinians to be renewed in September or October. He said a date would be set after he visits Sadat late next month and then meets with President Reagan in Washington on Sept. 8.

Reuter news agency added from Tel aviv :

Israeli Foreign Minister Yitzhak Shamir said the exclusion of the PLO from negotiations on Palestinian autonomy in Israeli-occupied areas was a condition for their success.

In an interview on Israeli Army radio, Shamir also said he was encouraged that Reagan and Haig had reject Sadat's proposal that the Americans invite the PLO to take part in the talks.

"If there is any hope that the negotiations will lead to an agreement in the near future, it is on condition that all contact or arrangements with those organizations whose aim and reason for existence is the destruction of Israel are excluded from all the calculations," Shamir said.

The autonomy talks, begun in June 1979, were suspended at the beginning of this year.