Royal Bank of Scotland and Sempra Energy have received bids worth about $4bn for their commodities joint venture RBS Sempra from a trio of banks.Deutsche Bank, JPMorgan Chase and Australian bank Macquarie made an offer by the Wednesday lunchtime deadline, according to reports today.RBS has been forced to sell its 51% interest in the business to comply with European Union state aid requirements following its bail-out by the UK government.RBS, now 70% owned by the UK taxpayer, acquired a controlling stake in Sempra Commodities for $1.7bn in 2008. Its partner Sempra Energy is also considering selling its 49% stake alongside RBS, the reports said even though it has the option to buy the business back.RBS Sempra is a big player in the London metals market, while its energy business is built around US utility subsidiary Sempra Energy.