KHOR FAKKAN, United Arab Emirates (AP) _ Shipping executives say Kuwait is in contact with U.S. officials to set a ''zero hour'' for removing the Kuwaiti flags from 11 tankers and replacing them with the Stars and Stripes.

President Reagan has proposed reflagging the Kuwaiti tankers to protect them from attacks from Iran and ensure the safety of the oil supply transported through the gulf. Iran accuses Kuwait of backing Iraq in the 6 1/2 -year-old gulf war.

The tankers have already been given American names. Soon they will have American skippers and, on paper at least, be owned by a company based in Delaware.

The shipping executives, who spoke on condition they were not identified, said Monday that Kuwait was discussing the timing of the transfer with Washington. No date has been announced.

Khor Fakkan is the major port outside the Strait of Hormuz where tankers usually stop for supplies on their way to or from the gulf.

It is off this port that U.S. warship protection would be arranged, with the escorts picking up their charges and following them through the gulf waters, according to shipping executives.

The 401,382-ton tanker Al-Rekkah will henceforth be known by its Americna name, Bridgeton. The 294,739-ton Kazimah has become Townsend and the 290,085- ton Al-Funtas took the name Middleton.

Other, smaller tankers ranging in capacity from 46,723 to 81,283 tons changed names from Umm al-Maradem to Sea Isle City, Umm al-Aish to Surf City, Umm Matrabah to Chesapeake City, Umm Casbah to Ocean City, Gas al-Burgan to Gas King, Gas al-Managish to Gas Prince, Gas al-Ahmadi to Gas Princess, and Gas al-Kuwait to Gas Queen.

At least three of these tankers - Kazima, Umm Casbah and Al-Funtas - have already been victims of air and sea attacks by Iran.

The vessels, once under the American flag, will be given protection by up to 10 U.S. warships.

In Washington on Monday, the chairman of the House Foreign Affairs Committee said he doesn't expect Congress to block Reagan's plan to reflag the tankers.

''As far as any congressional action goes, I don't see it,'' said the chairman, Rep. Dante Fascell, D-Fla. ''The policy has been announced and the die is cast, and I don't think Congress can do anything now.''

The plan has been criticized by some lawmakers in congressional hearings. On Monday, Kuwaiti Oil Minister Sheik Ali Khalifa al-Sabah warned that Kuwait would seek protective flags from the Soviet Union or other nations if Congress blocked Reagan's plan.

''It is up to Congress and the administration to decide whether it is in the interest of the United States to reflag Kuwaiti tankers,'' he said at a news conference in Kuwait on Monday. Kuwait already has chartered three Soviet tankers to move crude oil to contract customers.

''After giving everybody a chance, we would be satisfied to get our tankers reflagged by the Soviet Union. We will turn to other countries to reflag our ships if Congress denies us this. We have approached three countries - Britain, France and China,'' he said, adding the three had ''not responded so far'' but ''did not turn down our request.''

One maritime shipping executive interviewed in the United Arab Emirates on Monday said that when the 11 Kuwaiti tankers are reflagged with the Stars and Stripes, they also ''will get new official numbers, new call signs, and new carving marks - the legend bearing the port of registration.''

The American captains are to be flown two days before the reflagging to wherever each of the 11 tankers are located, shipping officials said.

In keeping with company policy, the maritime shipping executive spoke on condition of anonymity.

Kuwaiti ships are being increasingly singled out for attacks by Iranian gunboats and high-speed motor launches. Iranian Revolutionary Guards also have been planting mines in the approaches to Kuwait's Al-Ahmadi oil terminal.