He may be six feet under but that hasn't stopped Graham Greene from releasing his latest novel. This week, the English literary giant made a remarkable comeback.

The Strand magazine published the first of five excerpts from his newly discovered but unfinished novel, The Empty Chair.

Greene's work is one of several previously unheard-of manuscripts by some of the greatest names in modern literature that have recently been unearthed, and are now being published in the United States.

The manuscripts, which have lain hidden in archives and homes across the country, include works by Ernest Hemingway, Mark Twain, Vladimir Nabokov, William Styron, Mary Shelley and JRR Tolkien.

They are a welcome bonus to a publishing industry struggling to make ends meet in the midst of the economic downturn and eager to do anything to boost book sales.

"Publishers are struggling to find ways to stay in the black. If bringing out works by known authors can do that, they should publish them -- dead or alive," Carolyn Kellogg of Jacket Copy, the Los Angeles Times Book Blog, told the Weekend Review.

And already, it seems, the beleaguered book industry is reaping results from the revival of these dead authors.

In March, Strand, a literary magazine devoted to crime and mystery fiction, also published a previously unknown story by Mark Twain -- The Undertaker's Tale -- in addition to a lost story by PG Wodehouse.

"From the response we've received in terms of subscriptions and press coverage, I would say there is a huge public appetite," said Andrew F Gulli, managing editor of Strand.

With a predetermined fan base already familiar with their work, publishing the lost manuscript of a long- gone author is like "manna from heaven" according to Laura Dawson of the publishing consultancy firm LJN Dawson.

But there can be pitfalls. Take the new Graham Greene novel, for example: a murder mystery set with a dead body and a weapon, but no final chapter.

The manuscript -- written in longhand -- was discovered in the Greene archives last year by a French scholar, Francois Gallix, at the Harry Ransom Centre at the University of Texas.

There are "several options" on the table in figuring out how to end the book, Strand editor Gulli told the Weekend Review.

One option includes hiring a writer or asking readers to enter a contest to write the final chapter.

Written when he was just 22 and working as a sub-editor at The Times of London in 1926, The Empty Chair, a murder mystery, is believed to be Graham Greene's first stab at a novel.

And according to literary insiders who've already had a sneak preview at the manuscript, it's not a very good one.

"I'm no Graham Greene expert, but I found it to be a cute Agatha Christie knockoff, lacking the emotional depth and cynicism of his published work.

In other words, it wasn't bad -- but it wasn't good, either," said Carolyn Kellogg.

But Gulli -- an admitted Greene devotee -- insists that his magazine would never publish an inferior piece of fiction: no matter how famous the author.

"Everyone is entitled to their own opinion, as a person who has read everything that Greene has written, I can say that this a fantastic piece of fiction which is very representative of Greene," he said.

"We won't publish something in the Strand unless the work is of a superior quality. If I received The Empty Chair from an unknown writer I would publish it in the Strand in a heartbeat."

But the rush to find -- and publish -- the lost works of some of literature's greatest names begs the question as to whether the publishing industry should be reviving manuscripts that some authors wanted to die alongside them.

"Some drafts of stories or novels were never intended for publication," said Anthony Rainone, a freelance writer in Brooklyn, New York.

"Usually, it's for good reason -- maybe nothing more than the writer just isn't satisfied on a creative level.

"I know that drafts of stories I have never tried to publish shouldn't be published" he said.

This autumn, Playboy magazine will publish excerpts from the final lost manuscript of Vladimir Nabokov, author of the still-controversial novel Lolita.

Nabokov apparently so hated his unfinished manuscript -- The Original of Laura -- that he left strict instructions to destroy it when he died.

But following his death, his wife demurred and instead left it to languish in a safety-deposit box.

"After much consideration, his son has decided to publish it. Against his father's wishes? Yes," said Carolyn Kellogg.

"But his father also tried to throw Lolita in the fireplace -- if his wife hadn't stopped him, we wouldn't have that great work."

One of the justifications for resurrecting the work of a dead author is that it can offer new insights into the lives -- and writing styles -- of novelists who have already been endlessly scrutinised and dissected.

"We can see how the style of these writers changed over the years. We can, in Twain's case, look at why he wrote The Undertaker's Tale and realise that he wrote it after the death of his niece.

"He sort of had a lifelong war with undertakers," Gulli told the Weekend Review.

"In Greene's case, the year he wrote The Empty Chair was the year he decided that he wanted to become a writer."

And for those fans who had thought they'd read the last word of their long-gone favourite author, the opportunity to read a newly discovered manuscript can bring a jolt of happiness.

Gulli said: "When new works are found and published, it's a joy for fans of the works of writers like Twain and Greene. They realise that they have something else to look forward to by one of their favourites, and for people not familiar with their work.

"It introduces their work to a new generation of readers," he added.

Anthony Rainone knows that feeling. The crime fiction writer who calls Mark Twain "the father of American fiction" felt a rush earlier this year when he realised that he would soon lay eyes on a newly discovered work.

"When Andrew Gulli told me he was going to publish a previously unknown Twain short story, I stopped breathing for a second. It was truly a gigantic moment for me," he said.

Rainone, who said that "reading something new is like a visit from a friend long missed", also relished the opportunity to introduce Twain to an entirely new audience.

"I also realised it was a way for other readers to connect to this past American great. Maybe rekindle that spark for them, or introduce them to Twain for the first time. I definitely felt my adrenaline rushing."

With new archives opening their doors as never before, publishing experts are rubbing their hands at the prospect that hundreds more unfinished or unseen manuscripts may yet be discovered.

For some, like Carolyn Kellogg, who said she would "cry with joy" if one more book by Raymond Chandler in his prime was discovered, there is also some trepidation of what may be lurking in the shadows.

'Like Dr Frankenstein, you can't be sure what exactly might rise from the dead, right?" she said.

But for others, like Gulli, who has already struck literary gold with the new Graham Greene novel, the search continues.

"I think Graham Greene was the greatest author of the 20th century and this experience of mine of seeing his name in print in the magazine I edit ... I don't think it gets any better," he said.

"Now, along the way, if something pops up from Dostoyevsky, who I think was the greatest writer of the 19th century -- then I wouldn't know where to start!"