Many retail investors are set to miss out on shares in BT Financial Group's spin off funds management business, BT Investment Management (BTIM) when it floats later this year.

Shares of the new group will only be available to eligible Westpac shareholders, the parent of BT Financial Group, eligible BTIM employees and selected institutional investors.

"While some of my clients are in Westpac and are able to take part, I was bitterly disappointed that many more were unable to participate and get into BT," Conscious Money founder Wayne Lear said.

"I am though excited for the BT team and hope the culture will return to a more personal one, the way it was before the Westpac tie-up."

The initial public offering (IPO) is expected to raise approximately $247 to $292 million from the Westpac and the institutional offers.

Around $13.7 million of the proceeds will be retained to fund the purchase of shares for future equity grants to employees.

The group is expected to debut on the Australian Securities Exchange in mid-December.

Westpac shareholders in Australia and New Zealand who held Westpac ordinary shares were invited two weeks ago to pre-register a prospectus for the IPO.

At completion of the IPO, Westpac shareholders and institutional investors will hold around seven per cent and 33 per cent of issued shares respectively.

The indicative price range is set at $4.80 to $5.50 per share, which results in an equivalent market capitalisation of $768 to $880 million for BTIM.

BTIM represents approximately 10 per cent of BT Financial Group earnings and under one per cent of Westpac's overall earnings.

BT Financial Group will remain wholly owned by Westpac.

BTIM has around $42 billion under management held and is the eighth largest funds management business in Australia.