Demand for e-books to be read on electronic devices is on the rise.

The manager of acquisitions for Halifax Public Libraries says she is not buying new e-book licenses from HarperCollins after the publisher increased the price of digital editions.

HarperCollins used to offer unlimited lending on each e-book license but since the beginning of March the company has changed the policy. It now requires libraries to repurchase licenses after a limited number of uses.

"In [the new] model, we can circulate them 26 times and then we have to buy an additional one," said Debbie LeBel, the manager of collection development for Halifax Public Libraries. "Sadly, if it was a print book we could – in most cases – certainly circulate it well over that before we would ever have to replace it."

LeBel said demand for e-books has been growing steadily in recent years. Last year, Halifax Public Libraries doubled the size of its collection. HarperCollins titles account for about one in every five e-books in the collection of more than 6,000.

"They're always in perfect condition and we never have to replace them, although sometimes we have to buy additional copies because of demand," LeBel said.

For now, LeBel said she is choosing not to buy any new HarperCollins licenses although she continues to buy from other publishers on an almost daily basis. She said librarians across Canada have told her they are doing the same.

"At this point it caught us all by surprise so we were not prepared for it," she said. "We are just kind of watching the industry to see what happens."

LeBel said she is concerned that other publishers might follow HarperCollins' model or start charging more for e-book licenses, putting a large strain on the budgets of public libraries.