A record for suburban office buildings has been broken in Melbourne after a marathon 52 bids at auction that resulted in a two-storey building sell on a yield of 3.2 per cent, reflecting the incredible heat in the market.

Canadian giant Brookfield Asset Management has signalled its intent to be a major player in Australia's healthcare sector with an aggressive $4.35 billion bid for Healthscope, trumping a rival private equity bid for the nation's second largest private hospital operator.

Demand remains strong for Melbourne and Sydney "trophy" properties but overall sales are slowing because of tougher lending conditions, particularly in the $3 million to $5 million sector, according to real estate specialists.