Under Spanish law, a company is obliged to launch a full takeover only bid if it already owns 50% or if it has a majority of the seats at the board table. Metrovacesa's shares surged 21% on the news after the stock market regulator lifted a trading suspension imposed on the stock on Wednesday.

The bid price is about 25% above Tuesday's closing share price and 38% above Metrovacesa's average share price over the past six months.

The Sacresa statement says the firm would make its bid through its Cresa Patrimonial unit, an operating arm of the family-owned business led by chairman Roman Pons Sanahuja. A board member of Metrovacesa, Sanahuja raised his stake to 25% in January. A statement by Sacresa seemed to scotch early rumours it might be preparing to bid for the whole of Metrovacesa.

The statement adds: "It is Cresa Patrimonial's intention to maintain continuity regarding Metrovacesa's activities, as well as retaining the chairmanship and the current management team."

In a separate statement, Sacresa officials said: "Cresa Patrimonial considers its stake in Metrovacesa as a stable investment with a future and understands that the bid made is a step forward in its strategic objective of long-term diversification." Sacresa mainly sells residential homes, while Metrovacesa's business is strong in commercial rentals, more stable and less subject to cyclical swings. The news also appeared to help shares in French firm Gecina , which Metrovacesa bought last year. Gecina's shares were up more than 7%.