Prime Minster Tony Abbott has announced another round of musical chairs at for Canberra’s public service chiefs, but put off naming a replacement for outgoing Treasury head Martin Parkinson.

High profile Secretary of the Department of Health, Jane Halton will take on the role of nailing down government expenses as the head of the Department of Finance as a replacement for David Tune who has opted to retire from the Australian Public Service and will finish-up his term at the end of this week.

The move by Ms Halton to Finance, for a five year appointment, is likely to fuel continued speculation that she is a likely successor to incumbent APS chief and Secretary of the Department of Prime Minister and Cabinet, Dr Ian Watt.

Dr Watt holds the honour of holding the Secretary’s seat at Finance for the longest continuous period January 2002 to 30 August 2009.

Although there has been ongoing speculation within public service ranks over Ms Halton’s ambitions to take the top federal public service job, it is believed that there is little political appetite for a change until the present round of bargaining over the bureaucracy’s enterprise agreement is concluded.

Meanwhile, Mike Mrdak has been reappointed as the Secretary to the Department of Infrastructure and Regional Development for another three years after being in the hot seat for five years.

Mr Abbott singled out Mr Mrdak for praise and congratulation, saying that he had led his portfolio “with distinction”.

However there are still two key top public service roles yet to be filled, with Mr Abbott saying that an announcement on who will lead Health would be made Health “in the near future.”

With Martin Parkinson set to leave his job as Treasury chief in mid-December this year, the Prime Minister said he would “announce arrangements for the position of the Secretary of the Department of the Treasury at a later date.”