Hammerson has turned down Klépierre's second approach, saying the new €5.7B (£5B) proposal continues to undervalue the company.

However, the co-owner of the Dundrum Town Centre said it is still open to offers from Klépierre as long as it "properly reflects the value of the company" according to Independent.ie.

This time Klépierre valued Hammerson at 3% (£6.35 per share) more than in their previous proposal. The French firm intended to pay half in Klépierre shares and half in cash.

Klépierre has until April 16 to declare another intention to make an offer for the retail group, or to announce that it is stepping back and not making an offer, under U.K. rules.

"The revised proposal represents only a marginal increase to Klépierre's unsolicited proposal of £6.15 [per share] made on March 8, which Hammerson's board unanimously rejected on the basis that it very significantly undervalued Hammerson, its track record of delivery, the quality of its portfolio, its market positions, and the opportunities it has for future value creation," the U.K. property group said.

"Accordingly, the board of Hammerson, having assessed the revised proposal with its advisers, believes it is not at a price that justifies further engagement with Klépierre and has unanimously rejected it," Hammerson Chairman David Tyler said.

Hammerson owns 50% of Dundrum as well as half of the Ilac Centre and 50% of the Pavilions shopping centre in Swords.

The finalisation of U.K. rival Intu's acquisition by Hammerson has been delayed until it is clearer what approach Klépierre pursues with Hammerson.