By Christine Kearney

NEW YORK (Reuters) - In yet another sign of the growing dominance of the digital publishing market, the oldest English-language encyclopedia still in print is moving solely into the digital age.

The Encyclopedia Britannica, which has been in continuous print since it was first published inEdinburgh, Scotland in 1768, said on Wednesday it will end publication of its printed editions and continue with digital versions available online.

The flagship, 32-volume printed edition, available every two years, was sold for $1400. An online subscription costs around $70 per year and the company recently launched a set of apps ranging between $1.99 and $4.99 per month.

The company said it will keep selling print editions until the current stock of around 4000 sets ran out.

It is the latest move Encyclopedia Britannica has made to expand its Internet reference services and move farther into educational products. It first flirted with digital publishing in the 1970s, published a version for computers in 1981 for LexisNexis subscribers and first posted to the Internet in 1994.

The print edition became more difficult to maintain and wasn't the best physical element to deliver the quality of our database and the quality of our editorial," Jorge Cause, president of Encyclopedia Britannica, Inc., told Reuters.

Yet even as publishing industry has created more digital products, it has struggled with financial losses, and Cauz admitted to a "long road to profitability" for many publishers.

"Britannica was one of the first companies to really feel the full impact of technology, maybe twenty years ago, and we have been adapting to it, though it is very difficult at times," he said.

While Encyclopedia Britannica has continued to operate, he expected "many trade publishers will not survive -- and any content development company will have to be thinking about how they are going to fill the gap."

As to whether print editions of books will be viable products in the future, Cauz predicted, "print may not completely vanish from the market, but I think it is going to be increasingly less important. Many publications will never have a print analog and will only be printed on digital formats."

With its scholarly, reliable reputation, Encyclopedia Britannica had not been affected by the popularity of free online website Wikipedia, he said.

(Reporting By Christine Kearney)