Potential bidders will get information packages from next week, they said.

They have been preparing an initial public offering (IPO) of the German speciality publisher for April 2013 but are now launching a parallel sales process in hopes that an outright sale will generate greater proceeds, the sources said.

Springer Science, the world's second-largest publisher in science, technology and medicine after Reed Elsevier, and EQT declined to comment. GIC was not immediately available for comment.

An IPO remains the preferred option, two people close to the transaction said, adding that advisory boutique Lilja has been mandated alongside Goldman Sachs and JP Morgan to help organise the flotation.