The American Bar Association has given Robert H. Bork its top rating of "well-qualified" for appointment to the Supreme Court, but sources familiar with the vote said five lawyers on the 15-member committee dissented, with four voting that Bork is "not qualified" and one voting for the middle ranking of "not opposed."

The split vote on Bork, whose Senate confirmation hearings are to begin next week, reflects the biggest division on the influential ABA Standing Committee on the Federal Judiciary on a Supreme Court nominee since a vote on Clement Haynsworth in 1969.

In contrast, the committee gave unanimous "well-qualified" ratings last year to Chief Justice William H. Rehnquist and Justice Antonin Scalia. In 1969 and 1970, the committee unanimously endorsed nominees Haynsworth and G. Harrold Carswell, both federal judges. After it was disclosed that Haynsworth had failed to disqualify himself from cases in which he had a financial interest, the committee reconsidered and approved him 8 to 4 on a second vote. The Senate ultimately rejected both nominations.

In a statement, President Reagan said he was "especially pleased" by the rating and urged Bork's quick confirmation, citing "this endorsement from the ABA."

However, Senate Judiciary Committee Chairman Joseph R. Biden Jr. (D-Del.), said the large negative vote would be "amazing," if true.

"That's a big deal," Biden said at a luncheon with Washington Post reporters and editors. "If that's the case, something's up." He said any divided ABA vote on a Supreme Court nominee is highly significant.

Groups opposing Bork's confirmation were encouraged by the ABA's action. Nan Aron, executive director of the Alliance for Justice, called the vote "wonderful news, particularly in light of the '82 vote" in which the ABA committee unanimously rated Bork "exceptionally well-qualified" to serve as a federal appeals court judge.

Under the ABA guidelines, a "well-qualified" rating means the nominee "is among the best available for appointment to the Supreme Court." A "not opposed" rating means that the nominee, "while minimally qualified, is not among the best available" and a "not qualified" rating means the nominee does not meet the ABA's standards for professional competence, judicial temperament and integrity.

The ABA uses different categories and standards for evaluating lower court nominees, with "exceptionally well-qualified" as its highest rating.

In informing the Justice Department and the Senate Judiciary Committee of its rating, the committee, which voted Tuesday, did not specify how many members dissented or state the reason for the disagreement.

However, committee chairman Harold R. Tyler Jr., a former federal judge, said he would disclose the vote count if Biden asked him about it when ABA officials testify at Bork's confirmation hearings.

Bork has come under fire from civil rights and civil liberties groups, which contend he is an ideologue whose addition to the high court would threaten an array of decisions on such subjects as abortion, civil rights and school prayer.

As described in an ABA pamphlet, the committee, in evaluating judicial nominees, "does not investigate the prospective nominee's political or ideological philosophy, except to the extent that extreme views on such matters might bear upon judicial temperament or integrity."

Assistant Attorney General Stephen Markman, who was informed by Tyler of the split rating yesterday, said the administration "is taking a lot of satisfaction" in the ABA vote. "This is a well-qualified vote by a large majority of the committee," he said. "Obviously, you'd like to get a unanimous vote."

Citing Bork's earlier unanimous "exceptionally well-qualified" rating, Markman said it was "perplexing how individuals who came to that conclusion . . . could somehow find him not qualified for the Supreme Court."

The ABA pamphlet states that, "While the same factors considered with respect to the lower federal courts are relevant to an appointment to the Supreme Court, the committee's investigation is based on the premise that the Supreme Court requires a person with exceptional professional qualifications . . . . To fulfill the responsibilities of a Supreme Court justice, it is not enough that one be a fine person or a good lawyer."

In a related development, White House spokesman Marlin Fitzwater yesterday dismissed a federal judge's criticism of Bork's conduct in a case on the U.S. Appeals Court here.

Responding to a report in The Washington Post, Fitzwater said, "In the judicial process, there are always disagreements. This sort of thing is very normal." Fitzwater said the judge, retired U.S. District Court judge James F. Gordon of Kentucky, "has long had disagreements with Bork."

Gordon, in a letter to the Senate Judiciary Committee, said Bork -- assigned to write the majority opinion for a three-judge panel on which Gordon sat in 1983 -- tried to sidestep an agreement among the judges and replace the majority view with his own opinion. He said the actions called into question Bork's "basic honesty."

Fitzwater also said there were "some minor mistakes or omissions" in a White House briefing book on Bork that has been criticized as inaccurate and misleading, but he insisted that the "major points in there are accurate."

Biden last week released an analysis concluding that the briefing book misrepresented Bork as a moderate in the mode of retired justice Lewis F. Powell Jr., whom he has been nominated to replace.