The Senate Intelligence Committee scolded CIA Director William J. Casey yesterday for failing to disclose more than $250,000 worth of investments and nearly $500,000 in personal debts and contingent liabilities in the course of his appointment earlier this year.

Calling Casey "at minimum inattentive to detail," the committee said he also neglected to list more than 70 legal clients he has had over the past four years, four civil suits in which he was involved, and a number of corporations and foundations on whose boards he served.

Among the clients he failed to disclose despite applicable Senate rules were two foreign governments, South Korea and Indonesia, and an oil company controlled by the Indonesian government, Pertamina.

The senators, however, declared again, as they had tentatively done last July, that "no basis has been found for concluding that Mr. Casey is unfit to hold office as Director of Central Intelligence."

Casey responded to the six-page report by treating it as a complete vindication.

"I am pleased that the . . . committee, after an exhaustive investigation, has reported nothing which reflects on the integrity, the business practices and the ethical standards in which I have always taken pride," he said in a short statement. "I look forward to continuing to work together with the committee to improve the nation's intelligence capabilities."

In an outspoken dissent, one committee member, Sen. Joseph R. Biden Jr. (D-Del.), said he had lost faith in the CIA director despite what Biden called Casey's effective, decisive and imaginative leadership.

"Unfortunately, having reviewed the facts as disclosed in the committee's four-month investigation, I have come to the conclusion that Mr. Casey has displayed a consistent pattern of omissions, misstatements, and contradictions in his dealings with this and other committees of Congress," Biden said in a separate statement. "Consequently, I cannot support the committee's final report."

The rest of the committee's membership, eight Republicans and six Democrats, all voted for it although Sen. Patrick J. Leahy (D-Vt.) took exception to the "not unfit to serve" finding.

"This determination is best made by the president," Leahy said in a letter to Sen. Daniel Patrick Moynihan (D-N.Y.), the acting commitee chairman.

At a noontime news conference signaling official release of the report, Moynihan said that he would send a copy to Attorney General William French Smith with a cover letter inviting the Justice Department's attention to Casey's work for Indonesia and its state oil company, Pertamina, in 1976 in seeking a change in U. S. tax policy.

The committee said in its report that it had been unable to resolve the question of whether Casey should have registered under the Foreign Agents Registration Act, a step that he has contended was unnecessary because of an "attorney's exemption" in the law.

Moynihan said he would ask the Justice Department to look into the matter. Sen. John H. Chafee (R-R.I), who joined Moynihan in the news conference, cautioned against reading too much into the referral. The committee report called the question "a technical one."

At the time of Casey's confirmation last January, he filled out a Senate form that asked "Have you been an attorney for . . . a foreign government . . .? . . . Are you formally associated with individuals who are attorneys for . . . foreign governments?"

Casey's answer was: "Neither I nor my firm currently represent any foreign government or any foreign government entity." The report called this "unresponsive to the clear intent of the question," but the senators acknowledged that they should have followed up on this point last January.

According to the report, the committee did not pursue "certain specific matters" at any length because other government agencies had either resolved them or were in the process of investigating them. One issue involves ongoing IRS audits of Casey's 1977 tax returns and "of a limited partnership which Mr. Casey helped structure."

At the outset of the news conference, Moynihan took pains to emphasize the Intelligence Committee's need for "complete candor and attention to detail" from officials such as Casey in overseeing the intelligence community. But both he and Chafee insisted that they had no reason to think Casey had been "inattentive to detail" on intelligence matters.

At length, Moynihan acknowledged, in response to a final question, that this was because the committee "did not get into that" question at all. It looked "just at Casey's business dealings," Moynihan said.

In addition, the senators did not inquire into any stock transactions Casey may have engaged in since becoming CIA director although the position makes him privy to a vast and perhaps unique storehouse of worldwide economic information.

"To say we're should look over Mr. Casey's shoulder every time he writes a check . . . is ridiculous," Chafee declared. "We're just not going to do that."