A helicopter carrying the French ambassador and a French parliamentary delegation was hit by machine-gun fire and was forced to land today as it was taking off from a U.N. peace-keeping force base in southern Lebanon.

French sources at the residence of Ambassador Christian Graeff said the ambassador was escorting French legislators Jean-Francois Deniau and Andre Bellon on a visit to the French contingent of the U.N. Interim Force in Lebanon. The embassy said no one was hurt in the attack.

Local radio stations said the incident occurred near Tyre, about nine miles north of the Israeli-declared security zone.

"The bullets hit the fuel tanks which were full at the time, but the pilot landed safely and we took another chopper to east Beirut," Deniau told journalists later.

"If they want me to leave Lebanon . . . this is not the way, he added."

The identity of the gunmen was not disclosed. Iranian-backed Shiite extremists of Hezbollah as well as the more moderate Shiite Amal movement have forces in southern Lebanon. Today's was the latest in a cycle of attacks against foreign interests in Lebanon.

Three crew members, including an Italian colonel serving with UNIFIL were aboard the helicopter. U.N. sources said it was gunned down near the village of Maarakeh, a mile and a half east of Tyre, and headquarters of the French U.N. force. The French legislators had met yesterday with President Amin Gemayel and other Lebanese officials.

Earlier in the day six Lebanese security guards working at the U.S. Embassy in Christian east Beirut were abducted by Shiite extremists as they crossed into the capital's Moslem western sector. An embassy official said the six guards, all Moslems, were later released.

Leftist militia sources here said the six had been kidnaped because they did not heed warnings not to "work for the Americans."