The Twin Cities metro library systems could soon become the first in the nation to share e-books, vastly expanding the number of titles available to library patrons.

With e-book users complaining of long waits and limited selection from their local libraries, the change is a sign that e-book lenders are responding to the huge demand.

“Anything to have a wider selection would be great,’’ said Keeya Steel, 27 of Edina, an e-book user who guesses she has just a 50-50 chance of finding a book she’s looking for in the Hennepin County system.

Print books have gone back and forth across county lines on interlibrary loans for 50 years. But since 2010, when libraries started lending e-books, they have loaned them only to their own resident patrons.

But in the next few months, in time for the annual spike in e-book demand associated with e-reader holiday gifts, more than 100 metro libraries — those in the seven metro county library systems and the St. Paul Public Library — will share e-book titles via a 3M service called Cloud Link, an e-book lending service the company sells to libraries.

In an immediate boost for the new arrangement, expected to be approved on Thursday by the regional Metropolitan Library Service Agency (MELSA), the agency plans to spend as much as $500,000 for a common pool of e-books stocked with 2,264 of 3M’s most popular titles — eight copies of each. And, if the new sharing works well, it may buy as many more in 2014.

“We want to start out with a really big bang,’’ said Chris Olson, executive director of MELSA.

E-book demand is growing, and titles circulate so continually that readers often check out any title they can find just to be able to read something on their Kindles, iPads and Nooks. The new purchases and the sharing of collections mean e-book readers may for the first time have choices waiting for them, Olson said.

“We are being a national leader here,” Olson said. Although there are other consortiums that share a pool of e-books, “The idea of being able to share another library’s collection is the unique thing.’’

Unintended side effects?

The move will lead to a bigger pool of books — but also a bigger pool of users. Cheryl Theisen, 47 of Fridley, cringed when she first heard the idea because she thought it might mean more people vying for books. “It’s hard enough now,’’ she said.

To reduce her waiting time for the books she wants, she registered her card for use in two counties, Anoka and Ramsey. She tried to sign up in Hennepin as well but there were 79 people waiting for the book she wanted and she learned that Hennepin reserves its e-books for its residents.

If the new sharing system is “going to be a larger collection and I have a better chance of finding those books I’m excited,” Theisen said. But “I’ll believe it when I see it.’’

Because each library system has spent its own taxpayers’ dollars on e-book collections, each title will be available first to residents of the home county, Olson said. Also, patrons will not be able to get on the waiting list for books in other counties’ collections.

But the e-books that MELSA buys will be available to all libraries and to all patrons, and readers will be able to place holds on them as if they were in their home libraries.

MELSA is a state organization created to support cooperation and collaboration among the metro libraries. A large MELSA purchase of e-books will help libraries expand e-book offerings without robbing other parts of their budgets, Olson said.

The metro libraries will be the first to use 3M’s sharing software. “There really is not another vendor that does anything quite like this,’’ Olson said. Because 3M is based in Minnesota, “We are kind of thrilled that it’s in our back yard.” The new sharing system will be tested in the next few weeks in Dakota, Ramsey and Washington county libraries, each of which already has its own contract with 3M for e-book service. The other metro libraries are expected to join the sharing system soon, Olson said.

For libraries to be able to share with other libraries and serve their own patrons first was a complexity that 3M worked out over a year of developing the software, said Tom Mercer, marketing manager for 3M Cloud Library. “It’s been a very difficult feature to implement.”

The company expects the system to be in demand by libraries nationwide. Book publishers were originally leery of selling books in electronic form to libraries, fearing it would reduce book sales, but have grown more accepting of library lending. Still, 3M is going to enable e-book sharing only among libraries that are already closely working together, he said. “Publishers would get concerned if we had New York, Chicago and Los Angeles sharing books across the country.’’