The intensified interest from the consortium comes as Metro itself faces a takeover offer from prominent Czech and Slovak investors that values the firm at 5.8 billion euros.

The X+Bricks consortium said it was now offering total cash proceeds of significantly more than 500 million euros ($563.85 million).

Metro responded in a statement that it had received the offer but that it favoured a deal for the unit that is already in the works with another consortium led by real estate investor Redos. The two parties are in exclusive talks.

Those talks were going well, Metro said, adding that such a deal was in the best interests of shareholders, Real and Real's employees.

Metro's statement echoed the sentiments expressed by Redos's chief earlier in the day.

(Reporting by Michelle Martin; Editing by Arno Schuetze and Thomas Escritt)