The proposed change, which was announced by bourse operator Hong Kong Exchanges and Clearing (HKEX) in a consultation paper on Monday, has long been on the wish-list of bankers and investors in the Asian financial hub.
The time lag is particularly problematic when markets are volatile, as investors say it leaves them exposed to market falls between the shares pricing and trading.
"It is a once in a generation reform we have been wanting to do for a long time," Charles Li, HKEX's outgoing CEO told the media. The new arrangements replace the multiple existing separate channels and paper-based communication with a single digital platform for the exchange, IPO bankers, retail brokers and regulators, allowing listings to proceed more quickly.
HKEX does not expect to launch the new platform before mid 2022.
Jason Elder, a partner at law firm Mayer Brown, said the reforms were potentially a significant improvement as market risk and the manual process in the current arrangments "put Hong Kong at a competitive disadvantage compared to other global markets such as New York or London."
"It is also difficult to scale the current system for the really big IPOs or when you have a number of separate listings happening simultaneously," he added.
$38.8 billion has been raised in IPOs and secondary listings in Hong Kong so far this year, placing the exchange second globally behind the Nasdaq, according to Refinitiv.
Large secondary listings by companies including by New York-listed firms like Netease and KFC China operator Yum China acocunted for nearly half that total.
Li said the pricing-trading gap was particularly important for such companies whose shares were already trading elsewhere.
The consultation paper also proposes changes to reduce the impact of IPOs on Hong Kong dollar liquidity.
Hong Kong interbank lending rates surged in the build-up to Ant Group's $37 billion joint Hong Kong Shanghai IPO and hit nine-year lows after the listing was suddenly suspended earlier this month.
Currently, mass-market focused brokers must pay in advance for all the shares bid for by their clients, potentially tying up large amounts of cash.
Under the new proposals, brokers would only put up cash in advance for 10% of shares bid for by clients.
(Reporting by Alun John; Editing by Sherry Jacob-Phillips, Ramakrishnan M. & Simon Cameron-Moore)
By Alun John