Stephen King has pulled the plug on “The Plant,” his self-published online serial novel. The experimental and prolific author is taking a break to complete other projects but, according to his assistant Marsha DeFilippo, King is also suspending the project because too many people are downloading the work without paying for it.

In a statement posted on Stephenking.com, King told readers that after next month’s installment, he will be shelving “The Plant” for a year or two to accomplish other goals. Among them: finishing two novels and co-authoring “Black House,” the sequel to “The Talisman,” with Peter Straub.

“And my agent,” King continued, “insists I need to take a breather so that foreign translation and publication of ‘The Plant’ – also in installments, also on the Net – can catch up with American publication.”

Next month’s installment of the 10-part work will be free “as a way of thanking those readers [somewhere between 75 and 80 percent] who came along for the ride and paid their dues,” King wrote.

The explanation was written, DeFilippo said, before King received a final account of how many readers – only 46 percent – actually paid $2 for Part 4. The first three parts cost a dollar apiece. Parts 5 and 6, DeFilippo said, are being posted by King because they’ve already been written.

If King had known that so many people were downloading the fourth part for free, DeFilippo said, he would not even have written Parts 5 and 6.

“He’s not saying he’s not going to finish it,” she reiterated. “He’s just going to do other things in the meantime.”

King, whose other e-book, “Riding the Bullet,” caused a buzz in the electronic-publishing world last spring at a total price of $2.50 by credit card, posted the first section of “The Plant” – about a carnivorous vine that takes over a publishing house – in July.

He was up front with readers, explaining that he would continue to write the novel only if at least 75 percent of those who downloaded it paid for it.

“I think it was an interesting experiment,” said Len Kawell, director of e-book development for Adobe Systems. “The process needs to be incredibly simple. If Stephen King can’t do it, I would be suspicious if it would work for anyone.”

The Adobe platform is one of the ways that readers can view the online book.

Kawell suspected from the get-go that “people would not pay for it” if they didn’t really have to. He also thought that King’s idea to collect money after the fact on Amazon.com was “very cumbersome.”

Ideally, Kawell suggested, a reader will purchase an e-book from an online bookseller, then download it. King’s plan was “kind of an honor system.”

For his part, King was characteristically philosophical about the whole enterprise.

The sixth installment, he maintained on his Web site, “is the most logical stopping point. In a traditional print book, it would be the end of the first long section.”

He added: “You will find a climax of sorts, and while not all of your questions will be answered – not yet, at least – the fates of several characters will be resolved.

“Nastily. Permanently.

“Yet don’t despair,” King told his readers, informing them that he started “The Plant” years ago. “The last time ‘The Plant’ furled its leaves, the story remained dormant for 19 years. If it could survive that, I’m sure it can survive a year or two while I work on other projects.”