British real estate portal Rightmove rejected a sweetened $8.29 billion takeover bid from Rupert Murdoch's Australian property listing firm REA Group on Monday, saying the fourth bid still undervalued the company.

Rightmove said its board, after taking into consideration the views of shareholders and considering representations from REA's chair and management team, had concluded that the proposal put forward on Friday remained "unattractive".

Declining a request from REA to grant due diligence access, the British company also said that shareholder interests would be better served through the execution of its standalone strategic plan.

The latest proposal from REA Group, which is 62% owned by Murdoch's News Corp, consisted of 346 pence in cash, 0.0417 new REA shares and a special dividend of 6 pence in cash. That gave Rightmove an implied value of 781 pence per share, about a 3% increase over the previous bid.

Shares in the FTSE 100 company were down about 4% at 642 pence in early trade.

REA has until 1600 GMT on Monday to make a formal offer for Rightmove or walk away. It had requested to the UK's takeover regulator for an extension of the deadline.

Rightmove said that during the discussions, REA had requested to extend the deadline to allow it to consider a potential fifth proposal.

Rightmove said its Chair Andrew Fisher met with his REA counterpart Hamish McLennan and executive teams of both sides also held talks.

REA had expressed frustration at Rightmove's repeated refusal to hold talks.

Rightmove, the runaway house search market leader in the UK, has been battling fears of increased competition over the past year or so from rival OnTheMarket, which was bought by American property firm CoStar in 2023.

The UK company looks primed for a steady recovery from a property market downturn as the potential for more rate cuts boosts sentiment in the UK housing sector.

(Reporting by Aby Jose Koilparambil in Bengaluru; Editing by Subhranshu Sahu and Susan Fenton)