The administration is debating whether to use the Feb. 11 visit of Saudi Arabia's King Fahd as a vehicle for quick action on Saudi requests for a multibillion-dollar package of U.S. arms including 40 F15 jet fighters, U.S. officials and congressional sources said yesterday.

The sources said the debate centers on whether President Reagan should seize on Fahd's first trip here in eight years to wrap up a final agreement on the size and nature of the package and then announce it shortly after his departure.

While stressing that no decision has been made, the sources said administration sentiment strongly favors the sale, which was put off for almost two years to avoid making it an issue in the presidential election. But there is lively debate about timing.

State Department spokesman Bernard Kalb said yesterday, "It is correct to say that an arms package to enhance Saudi defense capabilities has been under consideration." But "until we are ready to notify Congress of such a sale, we will not comment further."

Defense Secretary Caspar W. Weinberger, backed by senior officials at the Pentagon and the Mideast affairs bureau of the State Department, are said to believe that Reagan should act quickly while he is riding the crest of his landslide reelection. In their view, fast action would prevent Israel's supporters from marshaling a counterattack in Congress, would calm Saudi Arabia's restiveness at the long delay and possibly induce Fahd to be more cooperative with efforts to revive Reagan's Mideast peace initiative.

However, the sources continued, that idea has encountered opposition from many congressional leaders who would prefer a long look at whether the Saudis really need so many sophisticated weapons. The congressional opponents reportedly include many Senate Republicans, who are aware that the sale could be a political liability for them in 1986, when 22 of them are up for reelection.

The sources said that Sen. Richard G. Lugar (R-Ind.), new chairman of the Foreign Relations Committee, who probably would have to take the lead role in the Senate, is aware of the acrimony sparked by earlier arms sales to Saudi Arabia. Many congressional sources say they think he is likely to lean toward a more deliberative, consultative approach. He has not made his views public.

Because of possible trouble on Capitol Hill, the sources added, Secretary of State George P. Shultz reportedly is undecided about the wisdom of moving quickly. Although Shultz favors the sale, some State Department sources describe him as hesitant to antagonize Congress and create potential problems for arms deals with other friendly Arab states such as Oman, Bahrain and possibly Jordan and Kuwait.

The total value of pending Saudi requests would be almost as large as the $8.5 billion sale to Saudia Arabia in 1982 of airborne warning and control system (AWACS) planes and other aircraft equipment -- until now the largest single U.S. military sale.

In addition to the 40 F15s, which would be added to the 60 purchased in 1978, the Saudis want roughly 3,000 Sidewinder AIM9L and AIM9P air-to-air missiles, 1,000 shoulder-fired Stinger antiaircraft missiles and an unspecified number of Maverick air-to-ground antitank missiles. They also want such controversial items as multiple-ejection bomb racks and additional range-extending fuel tanks for the F15s, and possibly more AWACS planes.

The officials who want to move quickly argue that it would bolster the U.S. strategy of building up Saudi Arabia's ability to counter possible Iranian threats to Persian Gulf oil supplies.

Many of these officials privately concede that the Saudi requests exceed the kingdom's needs. But they contend that any U.S. effort to cut the package substantially would offend Saudi leaders and renew the threat that the Saudis and other moderate Arab governments will turn to other countries, including possibly the Soviet Union.

Opponents argue that providing the Saudis with such items as multiple-ejection bomb racks would transform their F15s into offensive weapons that could threaten Israel, and that the size of the total package, coupled with expected future sales to other Arab countries, would erode Israel's edge in the Middle East arms equation.

These concerns would trigger a strong reaction from Israel's congressional backers, although it would be difficult for Congress to block the sale because the Saudis can pay cash and not depend on congressionally authorized credits. But opposition from Congress still could force the administration into another bitter, time-consuming fight.

The sale also could raise tensions with Israel. The sources said that Shultz, who reportedly has overcome objections from the Office of Management and Budget to an increase in U.S. military aid to Israel to about $1.9 billion for next year, also has offered Israel a commitment on U.S. military assistance for a three-year period.

However, the sources said, Israel has balked at the offer unless it has the right to seek larger amounts of aid if it feels that the Mideast arms balance has shifted.