Sweden came under renewed pressure to walk away from France Telecom’s $39.5bn informal takeover offer for TeliaSonera after the government’s main watchdog said the administration was not properly prepared to negotiate the highest price for its stake.

The National Audit Office issued a critical report that accused the government of failing to use “best practices” when it sold an 8 per cent stake in TeliaSonera last year and warned similar weaknesses threatened the coming sale of its 37 per cent stake.