Facebook, online taxi service Uber, US private equity firm Hellman & Friedman, and a consortium of German automakers BMW, Audi and Daimler are reportedly vying to buy Nokia's maps business.
A more bullish brokerage estimate by Inderes Equity Research values HERE at €4.4bn to €6.9bn, based on a sum-of-parts calculation.
Pursued by Reuters, Nokia, Facebook and Uber refused to comment while Hellman & Friedman, BMW, Audi and Daimler were not immediately available for comment.
Nokia said last week it had initiated a strategic review of HERE after announcing a €15.6bn takeover of smaller network equipment rival Alcatel-Lucent.
The HERE unit, one of Nokia's three remaining businesses after the sale of its handsets unit, has in recent years refocused to supply maps to automakers.
HERE also supplies online maps to major internet firms including Amazon.com, Microsoft, Yahoo and China's Baidu.
The Finnish company built its mapping and location business on the back of an $8.1bn acquisition in 2008 of US-based Navteq, a maker of geographic information systems used in the automotive industry.