News: RIO Deals of the day-Mergers and acquisitions

May 31 (Reuters) - The following bids, mergers, acquisitions and disposals were reported by 0930 GMT on Friday:

** Britain's competition regulator said it had started a probe into Nationwide Building Society's NBS.L proposed 2.9 billion pound ($3.7 billion) all-cash deal to buy Virgin Money UK VMUK.L .

** Spanish retailer group Dia DIDA.MC said it agreed to sell its business in Brazil for a "symbolic price" of 100 euros ($108.19) and exit the country to focus on more profitable markets such as Spain and Argentina.

** Debt-laden property developer Country Garden's 2007.HK venture capital arm is looking to sell its stake in Chinese chipmaker ChangXin Memory Technologies for 2 billion yuan ($276.30 million), Bloomberg News reported.

** Namoi Cotton (NAM) asked its shareholders to accept Singapore-based agribusiness Olam Agri's IPO-OLAA.SI A$144.9 million ($96.08 million) takeover offer for the cotton processing company.

** Rio Tinto (RIO) said it entered an agreement to buy Sumitomo Chemical Co's 4005.T 20.64% stake in New Zealand Aluminium Smelters (NZAS) to get full control of the country's only aluminum smelter.

** Skydance Media has submitted a sweetened offer for its proposed merger with Paramount Global PARA.O , according to a person familiar with the matter, the latest twist in a tumultuous negotiation process.