Vernon E. Jordan Jr., the president of the National Urban League, was shot in the back early today moments after emerging from a car at the Marriott Inn here.

He was rushed to Parkview Memorial Hospital before dawn. Jordan, 44, one of the most prominent and outspoken black leaders in the country, underwent more than four hours of emergency surgery and had part of his intestine removed.

He was taken off the critical list tonight and reported in "very serious" condition.

Police said Jordan was gunned down by a rifleman, evidently lying in wait, in a grassy area overlooking the hotel's parking lot.

In Washington tonight, FBI Director William H. Webster said there is evidence of an apparent conspiracy to deprive Jordan of his civil rights.

"That gets us in the case -- but we don't have the answer," Webster said.

He said the evidence indicates that the shooting was carried out by "apparently more than one person in a premeditated act."

Mayor Winfield Moses Jr. said that "at least one shot, probably two and possibly three" were fired. The shell casing of a 30.06 cal. rifle bullet was found in the grassy area and an expended bullet of the same caliber was recovered from the parking lot.

Police said that they had no suspects, but law enforcement sources said there were reports that the occupants of another car had "exchanged racial slurs" with Jordan about a mile from the hotel.

Riding with Jordan at the time was Martha C. Coleman, 36, a white divorcee. She is a member of the board of the Fort Wayne Urban League, whose annual dinner Jordan addressed Wednesday night.

Told that Moses had indicated that a racial motive for the shooting could be ruled out, Webster said, "It can't be ruled out."

At an afternoon news conference, Moses said the attack was carried out by "someone who understands guns and knows how to use them."

"It was not a Saturday-night type of shooting," the mayor emphasized. At one point, he said it had been "professionally executed" but later amended that to say, "'Expert,' I suppose, is a much better term than 'professional.'"

Local and federal authorities were plainly apprehensive that the shooting could touch off a racial outburst similar to the succession of urban riots that followed the assassination of the Rev. Martin Luther King Jr. in April 1968. Mayor Moses and Urban League officials joined in appealing for calm. No incidents were reported during the day.

"We feel very strongly that this community is not responsible in any fashion for what has happened here," the mayor said.

At a campaign appearance in Cleveland tonight, President Carter said he believed the assault on Jordan was "an assassination attempt." Carter did not explain the remark, but White House press secretary Jody Powell said later that the president had information from the Justice Department that there is "evidence that the attack was planned or premeditated rather than a spur-of-the-moment sort of thing."

Powell said Carter "was not attempting to assess motives."

Powell said the president had spoken by telephone with Jordan's wife and the surgeon who operated on him, and that Carter would visit Jordan, possibly this weekend.

Carter said the assault filled him "with a sense of outrage and a sense of sadness" because Jordan has spent his life "fighting against the causes of violence."

Authorities at first sought to discount the notion that the attack might have been racially motivated, but seemed to grow more uncertain as the day wore on. There were suggestions from police that it might have been "a domestic-type incident," but this was ruled out.

Fort Wayne police spokesman Daniel Gibson said Jordan and a woman companion, later identified as Coleman, left the Marriott around midnight after he had spoken at the local Urban League's annual dinner.

Authorities said the couple apparently went to Coleman's home. "It's our information Mr. Jordan was in a residential neighborhood having coffee with friends," the mayor said at his news conference.

The two returned to the hotel about 2:05 this morning in Coleman's red Grand Prix. Coleman was driving and, according to police, parked the car about 50 feet from Jordan's room at the Marriott.

"He got out and was walking around the rear of the vehicle when he was shot," the initial police account stated. "The female heard a noise, got out and found Jordan on the ground, bleeding profusely."

Coleman rushed into the hotel lobby. Desk clerks called police at 2:08.

The initial police account did not identify the woman by name or race nor did it state whether she had seen anyone fleeing from the scene.

FBI agents were quickly dispatched to assist local police and to determine whether any federal laws had been violated. Webster announced in Washington that he was ordering a full-scale investigation and would have as many as 20 FBI agents here by Friday morning.

"Based on information developed at the scene of the shooting, I have ordered additional agents to Fort Wayne to conduct an immediate and exhaustive investigation into the facts," Webster said. He declined to provide any details, saying that "such disclosure at this time could jeopardize our investigation."

The FBI originally said it was proceeding on the basis of a Reconstruction-era statute making it a federal crime "to injure, oppress, threaten or intimidate" individuals while traveling on the public highways.

Sen. Edward M. Kennedy (D-Mass.), in a campaign appearance in Cleveland this morning, called the shooting "another reminder of the senseless violence that stalks our land . . ." Kennedy flew here to visit with Jordan and his wife, Shirley, at the hospital.

The Rev. Jesse Jackson of Chicago, head of Operation PUSH, and Mayor Richard Hatcher of Gary, Ind., held a joint news conference at the hospital.

"We are here because we are hurt, we are traumatized and we are concerned," Jackson said. He said Jordan's wound was "seemingly a well-placed shot by a professional -- which is a political statement."

Hatcher said that "black leaders are being and have been destroyed in many different ways . . . Obviously one begins to wonder whether those are random occurrences, or whether it was no random accidental injury that Vernon Jordan has suffered.

In Washington, Attorney General Benjamin Civiletti said that "indications so far" are that the shooting did not appear to be related to Jordan's civil rights activities, and thus there was "no basis" for providing protection for other black leaders.

In addition to the rifle shell casing, police found signs in the grassy area that a body had apparently been lying there in wait.The assailant's perch was in a triangular area formed by a ramp of Interstate 69 and located an estimated 60 to 100 yards northeast of the spot where Jordan and Coleman parked the car.

An emergency medical team took Jordan to Parkview, where he underwent four hours of surgery. Doctors recovered some bullet fragments from his body. Jordan was also said to have suffered a leg wound, but it was not clear whether it contained any bullet fragments.

Dr. Jeff Towles, who performed the operation, said the critical shot entered the middle of Jordan's back, between his chest cavities and his pelvis, and left two or three small exit wounds.

"There was an explosive effect like nothing I've seen before," he said.

After Jordan was removed from the critical list, Towles said: "From a medical standpoint we're extremely happy at this point.

"It is miraculous he lived," Towels added. "The shot narrowly missed his spine."

Doctors said the civil rights leader was expected to recover.

Police said Coleman "did not see anything" after the shooting.

"I don't know if that was due to emotions or what," Gibson said. "She said it [the shot she heard] sounded like a thud, like a rock hitting the windshield. She turned around and saw him [Jordan]. Then she ran to the [hotel] desk and called police."

One of the guests at the Marriott, Patrick Gillespie of Chicago, heard a much more explosive sound from his fifth-floor room.

"It sounded like an M-80 going off right outside my window," he told reporters. "It rose me right out of my bed."

Gillespie said he ran to a window and saw a man leaning against the back of a red Grand Prix, yelling: "Help me. I've been shot in the back." bShirley Jordan, who is confined to a wheelchair because of multiple sclerosis, learned of the shooting around 5:30 a.m. from John Jacobs, an executive vice president of the Urban League. Too stunned and upset to talk to anyone at first, she arrived here this morning with her daughter, Vickee, a college student in Philadelphia.

The Jordans live on Fifth Avenue in New York City.

Jacobs said he spoke with Jordan briefly in his hospital room.

"I don't know why he was shot," the Urban League official said. "I don't think he knows why he was shot."

Officials said this afternoon that Jordan was "still very groggy."

"I don't believe police have fully questioned him at all," Moses said.

Coleman was reportedly being sequestered by police. She did not return to her two-story white frame home.

Reportedly married four times, she lives alone. She is a material scheduling supervisor at the International Harvester truck assembly plant here and has been on the local Urban League board for about two years. One acquaintance described her as "a very bright woman and a fine woman."

Among those appealing for the black community to remain calm in the wake of the shooting was Benjamin Hooks, executive director of the NAACP.

"When a national leader is shot, it creates an atmosphere of hysteria and . . . apprehension," Hooks told a news conference in New York. Citing the rash of assassinations in the late 1960s, he said, "There is definitely a psychotic element in this nation and one shooting can lead to others, no matter what the original cause was."

His concerns were echoed by Jackson, who said: "I would hope that our brothers and sisters around the country would not panic and go from genocide to suicide and massive rage."

Sen. Birch Bayh (D-Ind.) said the shooting was "tragic and senseless." He called Jordan "my friend and a great leader in the efforts to provide adequate housing, a decent education and jobs" for minorities, and said he was coming to visit him in the hospital.