Like so many readers, Gregory Mcdonald is finding Fletch, his breezy, hang-loose hero of books that have won two Edgar mystery awards, to be quite irrepressible.

Throughout three Mcdonald adventures, Fletch remains the same thoroughly engaging 30-year-old maverick reporter -- cocky, irreverent, an untamed free spirit.

"I do have a problem with Fletch," Mcdonald admits. "I had no idea it was going to turn into a series when I wrote the first book. If I had known, I wouldn't have left Fletch with $3 million in Rio."

It was a nice problem for an author to have had. And Mcdonald seems to be holding up well: Seven publishers bid in six figures for two new Fletch books at an auction last month; recently, Mcdonald says, he has turned down three of four movie offers each week. He says he's leery of what Hollywood might do to his books.

If Fletch hasn't yet left Mcdonald with $3 million in a Boston suburb, he does "put the ketchup on the table."

Mcdonald is in town as the guest of a gathering of mystery writers and fans called Bouchercon XI, the convention named for the late Anthony Boucher, novelist and critic. The weekend sessions, which opened last night at the National Press Club, continue today and tomorrow, beginning at 9 a.m. Among today's topics: "washington in Mystery and Suspense," "Sherlock Holmes: The Next 50 Years" and "The Reporter as Detective."

Fletch (for I. M. Fletcher -- a "nice, arrogant by-line," Mcdonald points out) first strolled on the crime scene in a book by the same name and promptly went on to snare the 1975 Edgar Allan Poe award given by the Mystery Writers of America for the year's best first novel. Two years later, he came back to win another Edgar for Mcdonald for the best paperback original, "Confess, Fletch."

Mcdonald is a not a writer to relax and stick with a successful formula. But Fletch won't let Mcdonald go nor will the readers. Conan Doyle had the same problem: He found that he had to resurrect Sherlock Holmes after pushing him over a waterfall.

"A genre is a horse," Mcdonald explains. "Either it rides you or you ride it. It's more exciting if the author is riding the horse. I went to try new things."

So after his third Fletch adventure, Mcdonald shifted to Francis Xavier Flynn, a Boston police inspector who sips chamomile tea and plays in string ensembles with his wife and five children. Then came a straight novel, "Love Among the Mashed Potatoes." Mcdonald's latest, "Who Took Toby Rinaldi?" is a roller-coaster thriller with a chase in an amusement park after an 8-year-old boy has been snatched as blackmail to kill a United Nations resolution affecting global oil politics.

But Fletch, who hasn't yet been pushed over a waterfall by his creator and probably would bob right up anyway, will be back. At the book auction last month, Mcdonald sold one finished manuscript and another future Fletch tale.

Fletch the reporter was nurtured in the newsroom long before Rossi began taking assignments on television's "Lou Grant." For seven years, Mcdonald worked for the Boston Globe, ending up as arts and humanities editor and critic-at-large with a weekly column.

"Journalism was marvelously seductive fun," Mcdonald remembers. "The character of Fletch embodies a lot of the myths and legends and of the newsroom when we sit back at 3 a.m. and tell stories."

In "Fletch's Fortune," the third in the series, Mcdonald had marvelously seductive fun in puncturing the posturing and pretensions of some media types. Part of the delight in reading the book is to match the characters to bylines or TV faces -- a ruthless, back-stabbing press tycoon (approximately stabbed in the back by scissors at a journalism convention), a syndicated columnist who writes snide accusations under the guise of investigative reporting, a tough, earthy woman reporter, a cigar-chewing humorist, a network pontificator who speaks only in polysyllabic words, a television interviewer who has clawed her way to the top.

"Soon after 'Fletch's Fortune' appeared," Mcdonald recalls, "my wife, Susi, brought in a very important-looking letter from the office of a network executive. I thought, 'Oh, boy, here comes a libel suit." Inside was one of the most charming letters that I have ever received. The executive wrote that he was at a convention like the one in the book, and everyone was reading about Fletch. He ended by saying that he survived both the murder and convention."

Mcdonald, a wiry, lanky man with the crinkled eyes of a sailor's squint, has a streak of Fletch's free spirit himself. When he decided to leave the newspaper business, he resigned on his seventh anniversary to the minute, at "12:20 noon," in April 1973. It was "poetry in resignation" to his soul.

"I was restless and had grown jaded," he explains. "I couldn't do anything that I hadn't done before. The summer before, when we were vacationing in Stowe, Vermont, my wife came into the room with a bourbon at some ridiculous hour like 3:30 a.m. and said to me, 'Look, you want to write novels. Better to try at 36 than 46 or 56.'"

So Mcdonald quit his newspaper job cold turkey with a wife and children and negotiated a loan at 9 percent interest, and Fletch began to emerge from his typewriter. He sent off three manuscripts to publishers. One came back with the seal broken and pages "scattered from Boston to New York." Another was returned unopened with the curt note: "We do not read unsolicited manuscripts." The third publisher was interested. Mcdonald's first payment was $2,000, and it took 18 months to pay off the loan.

Before the Fletch series, Mcdonald had written one novel, "Running Scared," after graduating from Harvard. He points out that the book now is in its fourth printing. When he wrote "Running Scared" in the early 1960s, Mcdonald was 23 and "swinging at the institutions of society."

"Now I think giving readers entertainment, and a laugh is a nice thing to do," says Mcdonald, in his 40s. "I wouldn't have made that statement 20 years ago. Then I felt a need to be important. By the time you are 36, you have known the pain, misery and boredom of life. The mystery novel is a framework on which I can hang stories I want to tell and comment about life and people."

To sprightly prose and crackling, crisp dialogue of the Fletch series has attracted Hollywood, which sees an engaging James Garner-like figure in the breezy renegade reporter.

Mcdonald has been to Hollywood for a round of drinks, lunches, parties and talks with studio executives.

"An executive says to me, 'Look, Greg, I see this girl coming down the street on a bicycle -- or it could be roller skates -- and this guy comes up. Is that a story?' It isn't a story to me."

Mcdonald also shares a touch of Fletch's iconoclasm.He has this vision of people living in isolated cubicles -- "Junior in the bedroom with a school computer, Dad working over a home terminal and Mother ordering groceries on a kitchen computer." It's frightening to Mcdonald, and he thinks reading and books are important to keep our humanity and balance.

And Fletch also would have understood Mcdonald's reasons for turning down all those Hollywood offers, even though it seems quixotic to some. After the first adventure left Fletch with $3 million in Rio, Mcdonald was having trouble extricating his hero from all that wealth for the start of a return appearance.

"I sat under a tree and talked to the dog," he recalls. "I finally worked it out. If Fletch didn't care about money when he didn't have it, then he wouldn't care about it when he did have it."