May 13 (Reuters) - Belgian real estate investment trust Cofinimmo COFB.BR said on Tuesday that the terms of a merger offer from healthcare real estate company Aedifica AOO.BR undervalue its stock, asking for a higher premium.
Aedifica launched its takeover bid this month, offering 1.16 of its shares for each share received, which it said implied a more than 20% premium to Cofinimmo's stock.
Cofinimmo said on Tuesday that the effective premium would be only 10.8%, based on its market capitalisation and the value of Cofinimmo shareholders' stake in the combined entity.
The trust said fully endorses the strategic rationale of the merger but called for a balanced and effective "merger of equals" and proposed that Aedifica should offer 1.21 shares per Cofinimmo share.
"A win-win transaction for both companies and shareholders is needed as well as a cooperative approach," Cofinimmo's statement said.
Shares in Cofinimmo were up 0.9% at 76.5 euros ($84.98) by 0918 GMT on Tuesday, giving it a market capitalisation of 3 billion euros ($3.33 billion).
Aedifica shares gained 0.8% to 66 euros, valuing the company at 3.2 billion euros.
($1 = 0.9003 euros)
(Reporting by Alessandro Parodi in Gdansk
Editing by David Goodman)
((Alessandro.Parodi@thomsonreuters.com;))