The UK government is planning to begin the sale of its majority stake in Royal Mail in September, Bloomberg reported, citing three people with knowledge of the matter.The sources said the postal service may announce its intention to float mid-month and the initial public offering (IPO) could open for investors in October. The potential valuation is pegged at £3bn.Theme park operator Merlin Entertainments Group and real estate broker Foxtons are said to be among the companies interested in the IPOs, the sources added.The Department for Business would not confirm specific dates but said the UK plans to sell Royal Mail during the current financial year. A Royal Mail spokeswoman also declined to comment on the timing or size of the IPO.Business Secretary Vince Cable announced in July the government's intention to dispose of a majority stake in Royal Mail, including 10% of shares that employees will receive for free.The disposal will be the largest privatisation in Britain since former Prime Minister John Major broke up the country's railway in the 1990s.The UK also has plans to privatise Lloyds Banking Group and RBS which are expected as early as September and next month, respectively.