FBI ballistics tests indicate that only one shot may have been fired at civil rights leader Vernon Jordan in the attack on him here this week, officials said tonight.

There were also preliminary indications that the bullet hit a metal chain link fence, perhaps saving his life.

Authorities initially believed that at least two and perhaps three shots had been fired at the National Urban League president as he emerged from a car early Thursday morning at the Marriott Inn here.

But what local officials had described as a largely intact bullet found on the hotel parking lot after the shooting turned out to be simply a large fragment, according to FBI officials.

FBI spokesman Tom Deakin said in Washington that the large fragment sent to the bureau's bullistics experts weighed 116 grains -- little more than half of a normal 220-grain bullet from a .30-06-caliber rifle.

Three other fragments, all recovered from Jordan's body during emergency surgery here, were analyzed.

Deakin said these included two pieces of copper jacketing, each weighing 5.3 grains, and a piece of core lead weighing 36.8 grains.

All told, the four pieces weighed a total of 163.4 grains, still less than a full-sized bullet.

"It's all consistent with being one bullet," Deakin said. "But that's the best you can say. You couldn't say in a court of law that it definitely was one."

He said there were not enough markings left on the different pieces to match them up conclusively.

As for the question of the bullet hitting the fence, Deakin said there was a mark on one of the pieces of copper jacketing indicating that it had hit metal before lodging in Jordan's body.

Neutron activation tests, which will take days, have been ordered to determine whether any metal residue on the copper-jacketed piece could have come from the fence.

Deakin said the 36.8-grain piece of lead was probably what struck Jordan in the middle of his back, making a hole that his chief surgeon said was almost big enough to put a fist in.

In contrast to the FBI view, Fort Wayne police said tonight they still believe two bullets were fired at Jordan from a grassy slope about 60 to 100 yards from the spot where Jordan was hit.

"We think the first bullet penetrated his torso and laid on the parking lot," one Fort Wayne police technician said. "We think the second one was the one that exploded."

He acknowledged, however, that local police conducted no ballistics tests of their own.