The Taranaki-based and community-owned TSB Bank has leapfrogged both NAB's BNZ and Westpac in New Zealand's KiwiSaver market, for government-subsidised savings, by buying a 26 per cent stake in Fisher Funds Management.TSB's investment is part of a deal that will result in Fisher Funds Management buying Tower Funds Management.The deal involves Fisher, which is run by the high profile New Zealand investor Carmel Fisher, buying Tower Investments for NZ$79 million. The investment will be funded with equity and debt from TSB.The TSB-Fisher combination will control NZ$5.5 billion of funds under management, which will make it the fourth biggest in the market after AMP (which recently merged with AXA), ANZ and ASB. This puts it ahead of Westpac and BNZ, the latter has only recently entered the KiwiSaver market in its own right.Fisher recently bought Huljich Funds Management to increase its KiwiSaver funds under management to NZ$1.6 billion. Industry players are pushing for the current 'opt-out' voluntary scheme with government subsidies to become more like Australia's compulsory super scheme.