I'M DYING LAUGHING: The Humorist By Christina Stead Edited and with a preface by R.G. Geering Henry Holt. 447 pp. $19.95

LITERARY executors, sometimes a blessing and sometimes a curse, are nevertheless an important part of the literary process: Writers die; they leave behind uncompleted manuscripts, early drafts, unpublished material of every kind. It's up to the literary executor to decide whether publication will add to or detract from the writer's reputation. Without Max Brod, Franz Kafka would have been known to only a few in Prague and Vienna. Brod's decision to ignore Kafka's instructions to burn the latter's manuscripts saved, or in a sense created, one of the great literary reputations of this century.

If the decision is to publish, then the manuscript must be edited. With how free a hand? James Agee's A Death in the Family, not quite completed, and F. Scott Fitzgerald's The Last Tycoon, only about two-thirds finished, published more or less as found, contributed considerably to the lasting fame of both writers. Did Willie Morris take too much upon himself when he completed James Jones' Whistle? Probably not. It was evidently only a matter of a chapter -- and besides, Morris did a good job. The reader never catches the break.

R.G. Geering had a much different sort of task with I'm Dying Laughing. When his fellow Australian Christina Stead named him as her literary executor in 1979, she told him of a novel on which she had worked for years and said he could feel free to publish it after her death if he saw fit. The decision was his when she died in 1983. As he writes in his preface, "She seemed to assume that the manuscript, after all those years of rewriting, was in a publishable form. What I inherited in fact, was a huge mass of typescript ranging in finish from rough to polished and in length from page bits to different versions of whole chapters, along with piles of basic and supplementary material." There are traces, and more than traces, of the novel's original chaotic state in this version which Geering has pieced together and now brought out.

Although Christina Stead spent only 10 years of her long life in the United States (1937-1947), she was for a time thought of as more or less an American novelist because she wrote so well about Americans. Four of her 12 novels are set in this country, including the book for which she will always be best known, The Man Who Loved Children (not exactly a Washington novel but probably the finest novel ever set in Washington). She knew Americans well, was married to one (William Blake, who was a writer and an economist), and once again she proves her understanding in I'm Dying Laughing with her central characters -- it is their book completely -- Stephen and Emily Howard.

They are Americans of a particular type just about extinct today -- wealthy Communists. The source of Stephen Howard's money is his family -- Chicago manufacturing. He's not exactly rolling in dough, for as "the family misfit," he is on a relatively modest allowance, yet it would have been enough to keep him and Emily without ever having to work a day. Emily is the real moneymaker. She maintains them in high style in New York, Hollywood and for a while in Paris with her best-selling novels, Broadway plays and screen stories. She's noted for her humorous touch, yet what she wants most, of course, is to write serious proletarian novels. And when she writes them, they don't sell. His answer: get back to work on the stuff that does sell.

When they meet in the '30s on the way to a Writers Congress in Paris, all this is ahead of her. She is from Arkansas, a newspaper reporter, and he is a rich boy out of Princeton writing articles for revolutionary publications. Yet with her success, they become as devoted to fine wine, good dining, expensive houses, first-class travel and luxury hotels as the "oppressors" whom they loathe. This is not done as light, quick satire. It is documented at length -- over-documented -- so that the novel seems an endless succession of similar scenes in which Emily declares her intention to do real work for the cause and Stephen tells her they have bills to pay. In between there are giddy, silly dinner parties in which what then passed as intellectual repartee is tossed recklessly about. There is a compulsive, even confessional tone to all this repetition. Could this have been the way that Christina Stead saw herself and marriage to William Blake? Surely not.

NEVERTHELESS, there are a few episodes in I'm Dying Laughing that are wonderfully well-realized. For example, the "Hollywood red" scene in which Emily and Stephen show up for dinner and, after the servants have cleared the table, find themselves on trial for their deviations from the Party line -- this speaks volumes in 40 pages about the confused social-political climate then current (1945) in Cloud Cuckooland. She is nearly as good, though not as succinct, at imparting the situation of the Left in France during the years just after the war. The separate, sad ends to which Emily and Stephen Howard come are also very strongy written, although they seem too much for two such fundamentally frivolous people.

And so this, after years of working over the manuscript, is what Christina Stead's literary executor, R.G. Geering, has given us as her final novel. He has my sympathy. It couldn't have been an easy job, and yet he didn't go far enough with it. At two-thirds its length -- say, about 300 pages -- it might have worked; in any case, it would have worked better.

As it is, I'm Dying Laughing will do nothing to elevate Stead's stature as a writer. On the contrary, after reading this, anyone unfamiliar with her work would not be encouraged to go on to those novels of hers -- among them, House of All Nations, The Puzzleheaded Girl and certainly The Man Who Loved Children -- that really do deserve to be read.

Bruce Cook is the author of "The Beat Generation" and "Brecht in Exile."