The central borrowing authorities of states and territories will continue to be able to rent the Australian government guarantee until the end of December 2010 for new debt, the Treasurer, Wayne Swan, said yesterday.State government borrowing agencies have recently found it cheaper to sell debt without the guarantee, such as the $4 billion bond sold by Queensland Treasury Corp late last month.However, some of the state agencies may want to top up lines of existing guaranteed bonds to foster liquidity, and they are being given until the end of the year to do so.