Big wealth managers and their upstart rivals have been tipped to follow Westpac's lead and cut fees for their investment platforms, underlining the fierce competition for fund share in the $888 billion market.

On Tuesday, Westpac's wealth management arm BT Financial Group said it would it cut the fees paid by new superannuation and investments clients using its Panorama platform, offering a 0.15 per cent asset-based administration fee, capped once their assets reach $1 million, along with a flat account fee of $540 per annum. The bank said it would take a $70 million hit as a result of the changes, which represent an average fee cut of 40 per cent.