Lebanese leaders hailed Secretary of State Alexander M. Haig Jr.'s declaration of concern for Lebanon as a separate Middle East problem today but questioned whether Washington really intends to do anything about it.

The skepticism, in reaction to Haig's speech in Chicago Wednesday, grew from seven years of civil war and other hostilities here during which Lebanese officials and ordinary citizens repeatedly have criticized the United States for failing to intervene with a solution which many Lebanese seem to feel could be found if only the U.S. government really wanted one.

Foreign Minister Fuad Butros expressed satisfaction that Haig singled out Lebanon as a major U.S. concern in the region, along with efforts to work out autonomy for Palestinians on the West Bank and prevent the Iran-Iraq war from spreading instability in the Persian Gulf.

"For the first time in eight years, U.S. officials have recognized that the Lebanese crisis is a crisis in itself and rates a place among international priorities," Butros declared after receiving Haig's speech from U.S. Ambassador Robert Dillon.

Haig pledged to dispatch special U.S. envoy Philip Habib and said: "The world cannot stand aside, watching in morbid fascination as this small nation with its creative and cultured people slides further into the abyss of violence and chaos."

Butros declined to comment on the substance of Haig's address, saying he would do so once he studied U.S. plans carefully. But columnist Michel Abu Jawdeh commented in an editorial, said to reflect the views of President Elias Sarkis, that if Habib wants to accomplish anything in Lebanon he must bring with him a new U.S. policy.

Persistence in the Camp David autonomy negotiations as a Middle East solution means the some 450,000 Palestinians in Lebannon will probably have to remain, Abu Jawdeh said, and this is something Lebanese reject. So attempts to solve the Lebanese crisis must also include a new approach to solving the overall Palestinian problem, he added.

"If Mr. Habib is going to return carrying thoughts that ignore these truths, then Haig's statement on Lebanon is going to be one of many," he wrote in An Nahar, Lebanon's most prestigious newspaper. "But if Habib is going to carry different thoughts and policies, then Lebanese will breathe a sigh of relief at the Amercian secretary of state's words, even if they continue to hate the man who spoke them."

Western diplomats here said the United States has not approached Lebanon with any new plan for resolving the crisis. It is difficult to imagine what could be done without at least a partial solution to the conflict between Israel and the Palestinian guerrilla movement based here, and this is nowhere in sight, they added.

One well-informed diplomat speculated that the new U.S. iniatitive will concentrate on devising a "framework" for drawing other nations into joint efforts to strengthen the central government.