STOCKHOLM: Swedish real estate company Castellum has offered to buy rival firm Kungsleden in a deal worth 26.9 billion Swedish crowns ($3.13 billion), the company said in a statement on Monday.The offer, comprising of 70% in shares and 30% in cash, was immediately backed by Kungsleden’s board in a separate statement made shortly after the offer.”Through the combination with Kungsleden, we strengthen our position as the leading Nordic listed commercial property company, with focus on the most interesting growth regions,” Castellum’s chairman Rutger Arnhult said in a statement.Castellum said Kungsleden has built an attractive commercial property portfolio with a strong balance sheet which would enhance Castellum’s competitiveness in the real estate market.The offer values Kungsleden shares at 124 crowns per share, a 7.5% premium on the share’s closing price on Friday.Kungsleden’s board unanimously recommended shareholders accept the offer.