Australian banks gain on Citi's hiked earnings forecast

** Australia bank stocks .AXFJ rise as much as 1.7%, their biggest intraday pct gain since August 31

** Citi raises earnings forecasts for major banks by 1%-2%, expecting higher business credit growth and stronger net interest margins due to higher rates and swap yields

** Citi sees additional RBA rate hike in September

** Brokerage says banks gain from growth in high-profile sectors such as data centres and utilities, along with services sectors where credit demand is increasing

** Citi upgrades National Australia Bank NAB.AX to "buy", saying it is best positioned to benefit

** NAB gains as much as 2.3%, highest since September 8

** YTD, AXFJ down 1.4%