John W. Dean III is a happy man these days.

Dean can’t tell you why in any detail, but he can say that earlier this month he reached an out-of-court settlement with St. Martin’s Press in a $150 million libel suit over a book that depicted him as the chief villain in the Watergate scandal.

“All I can say is that we’re satisfied,” Dean said, speaking for himself and his wife, Maureen. The former White House counsel whose testimony ultimately led to President Nixon’s resignation, Dean has previously denounced the book as “absolute garbage.”

A byzantine piece of revisionism published in 1991, the book, “Silent Coup,” depicted Dean as the driving force behind the Watergate break-in and the backstage architect of the cover-up that followed.

The authors, Len Colodny and Robert Gettlin, contend that Dean orchestrated the 1972 burglary at Democratic National Committee headquarters to protect his future wife, then named Maureen Biner, by removing information linking her to a call-girl ring that worked for the DNC.

The Washington Post’s Book World called it one of “the most boring conspiracy books ever written” despite its “wild charges and vilifications.” The New York Times Book Review assailed its depiction of Nixon as “an innocent victim” and said it showed “a stunning ignorance of how the Government under Mr. Nixon operated.” Sam Dash, the chief counsel for the Senate Watergate Committee, denounced it as “a fraud . . . contradicted by everything on the White House tapes and by the evidence.”

At the same time, the book won support from some historians and researchers, not to mention former Nixon aides such as John D. Ehrlichman and G. Gordon Liddy, the convicted Watergate burglar who is now a radio talk show host. “Silent Coup” was on the New York Times bestseller list for 12 weeks in 1991 and sold more than 100,000 copies, co-author Gettlin recalls.

Dean and his wife, who now live in Southern California, are still suing Colodny, Gettlin and Liddy, who has endorsed the notion that Maureen Dean was a prostitute.

St. Martin’s Press lawyer David Kaye confirmed the out-of-court settlement by the publishing house but said its terms were confidential. St. Martin’s is giving the publishing rights “back to the authors,” Kaye added. He said this was “common in publishing” for books published years ago.

Asked about monetary aspects of the settlement, Kaye replied: “I didn’t say any dollars were paid.” Dean said he was limited to two words: “We’re satisfied.”

St. Martin’s is continuing to publish hardcover editions of Liddy’s book, “Will,” with what Kaye said was “an updated postscript” in which Liddy makes clear he still believes “Silent Coup.” Dean said, however, that “there is nothing derogatory about Mo [Maureen Dean] in the new postscript” as there was in a paperback edition now out of print.

One of Colodny’s attorneys, Charles Carlson of Tampa, said they are waiting for Dean’s response to a lengthy motion for summary judgment that Colodny submitted months ago in U.S. District Court in Washington. “We’re still in the case,” he said.

Co-author Gettlin said he was, too. “I don’t want to speak for St. Martin’s or what they did,” he said. “This author stands fully behind the book.”

Liddy has no intention of settling, said his lawyer, John B. Williams. “There have been settlement discussions with other defendants, but not Gordon.” In the most recent postscript to “Will,” Liddy said he sees the lawsuit as providing “the American people with an opportunity to learn their real history.”

Dean said his response will be filed in court shortly. He said it will, of necessity, be “voluminous.”