The move would bring the postal service in line with Camelot’s four other stakeholders, which have all already indicated they are ready to sell their stakes.
Royal Mail is believed to have wanted to keep its slice, which could net it up to £85m, but has come under pressure to sell in a bid to cut its pension deficit, which is estimated to be as high as £10bn.
The four other stakeholders – Cadbury, bank note printer De La Rue, IT firm Fujitsu and defence group Thales – have already expressed their readiness to sell.
Camelot is understood to looking to attract about £425m with Virgin Group chief Richard Branson and the operator of the French lottery, Francaise des Jeux, which already works with Camelot on the Euromillions game, reported to be potential buyers.
Other reported potential bidders include private equity firms CVC Capital Partners and Cinven.