Finland's Nokia has confirmed that it has initiated a strategic review of its map business, HERE, after announcing a takeover of ailing Franco-American network equipment rival Alcatel-Lucent.

Nokia has hired a financial adviser to explore a sale of the unit, Reuters reported.

HERE is estimated to be worth €4.4bn (£3.2bn, $4.7bn) to €6.9bn, based on a sum-of-parts calculation, according to Inderes Equity Research.

Nokia said in a 15 April statement: "Nokia today announces that it has initiated a review of strategic options, including a potential divestment, for its HERE business. HERE is a leader in navigation, mapping and location intelligence.

"...The Board of Directors of Nokia believes this is the right moment to assess the position of HERE within the proposed new Nokia business.

"The strategic review of HERE is on-going and it may or may not result in any transaction. Any further announcements about HERE will be made as appropriate."

Earlier, the Finnish telecom equipment major said it had agreed to buy smaller peer Alcatel-Lucent in an all-stock deal valued at €15.6bn.

The boards of both companies agreed on the terms of the transaction, which is expected to be settled in the first half of 2016. The deal is still subject to approval by Nokia's shareholders, regulatory approvals and other customary conditions.