A confidential report inadvertently posted on the council's website on Monday has recommended the council withdraw from the Central Highlands Regional Library Corporation from June 30 next year.

But the council says the recommendation, if adopted, would not threaten library services in Ballarat or the jobs of library staff.

The corporation was formed in 1997 with six member councils: Ararat, Ballarat, Central Goldfields, Hepburn, Moorabool and Pyrenees.

Southern Grampians joined in July 2006.

The report said a 2009 strategic review of the library found that branches were under-staffed, the corporation was under-funded and its model unsustainable.

The report said the library's collection of more than 285,000 books, DVDs and other titles was steadily decreasing in size.

In August 2009, 1536 items were added to the collection, but 2463 items were withdrawn.

The library lagged behind state averages in a number of measures, including the turnover of its collection and the number of items per head of population.

At present, Ballarat City Council provides more than half the corporation's annual budget, but has one vote on the corporation board, the same as other councils.

The report outlines possible options for the running of library services in the region, including one in which a single council, probably Ballarat, would provide library services that other councils could purchase.

Ballarat City Council chief executive officer Anthony Schinck said the council was required by the corporation's constitution to give 12 months' notice if it wanted to withdraw.

But he said this did not mean library services or jobs in the region would be threatened.

"We don't want to get the region worried that there's not going to be any library services into the future, or cause any unnecessary angst to staff ... ahead of any decisions that will be made down the track."

He said the council wanted to find the best model for the delivery of library services.

The corporation operates branches at Ballarat, Sebastopol and Wendouree. There are also sites at Ararat, Bacchus Marsh and Hamilton, as well as a mobile library service.