Former vice president Spiro T. Agnew has sent a letter of apology to his former attorney, George White Jr., settling a $17 million defamation suit filed last year by White Against Agnew and a New York publishing firm for references Agnew made to White in his book, "Go Quietly . . . Or Else."

In the two-page letter, dated May 27, Agnew apologized for implying in his book that White, a longtime associate, "had any involvement in any campaign improprieties or were in any way involved in anything unlawful."

"I hope you will accept this letter as a statement of regret on my part for any misunderstanding that may have arisen . . . I also realize that I should have checked beyond my own recollections to verify the facts," Agnew said in the letter.

White filed the suit last June 24 in U.S. District Court in Baltimore, alleging that Agnew and William Morrow and Co., the book's publisher, were guilty of defamation of character, invasion of privacy and injurious falsehood. White said the 280-page book, published last year, contained "false statements and distortions from cover to cover," and put him in an unfavorable light.

White's attorney, James White, no relation, said yesterday that the book says his client did not help Agnew during a 1976 investigation of loans by the Pallottine Fathers, a Catholic religious order, because White was "nervous and under pressure" from having his "financial backers" investigated by the same U.S. Attorney's office investigating Agnew.

"I now realize that there was no investigation into anyone connected with you by the U.S. Attorney's Office at the time," Agnew says in the letter. "Obviously, since there was no such investigation, you could not (as I wrote in the book) have been concerned about one."

James White said yesterday that his client agreed the letter would be the only settlement because he "was never after any money." t

"These guys were awfully close at one time," James White said. "[George White] didn't want people who knew them both to think he was trying to get rich off of filing a suit and piling more troubles on Agnew. He just wanted to get the record straight."

Settling the suit with a written apology was discussed last August, James White said, when he and Agnew's attorney, Judah Best of Washington, talked during an American Bar Association conference.

Best said yesterday his client "is pleased that the case is concluded. It was just a case of two old friends getting together and resolving their difficulties."

White was forced to testify in April in a civil suit against the former vice president that sought the return of kickbacks Agnew allegedly received while governor Of Maryland and later as vice president. A judge ruled that since Agnew violated the attorney-client privilege by publishing accounts of his conversations with White about kickbacks, the lawyer's testimony about these coversations could be used in the case.

After a week-long trial, Anne Arundel County Circuit Court Judge Bruce Williams ruled April 27 that Agnew owed the state of Maryland $248,735 plus interest. The ruling has been appealed.

James White said yesterday that a copy of the letter would be sent to the Library of Congress along with Agnew's book, an account of his resignation as vice president.

The defamation suit will be withdrawn officially next week from the U.S. District Court in Baltimore, James White said.