With the Britain's divorce from the European Union confirmed on Friday, prominent Hong Kong-listed banks and companies with heavy business exposure to the United Kingdom were battered by a hefty fall in the stock market.

The benchmark Hang Seng Index snapped its five-session streak of gains to tumble by 2.9 percent on Friday, mainly led by the 9.48-percent plunge of London-based Standard Chartered Plc and 6.59-percent slump of London-headquartered HSBC Holdings Plc.

Li Ka-shing's CK Hutchison Holdings Ltd sank 5.07 percent, while Cheung Kong Infrastructure Holdings Ltd and Power Assets Holdings Ltd retreated by 5.48 percent and 4.76 percent, respectively.

Analysts said these stock losses could spell the beginning of a torrid time that companies and banks with UK exposure will suffer going forward.

The most instant risk from a Brexit facing those companies would be a continuation and even an extension of the hefty depreciation of the pound against a wide range of currencies experienced on Friday. Another billionaire, US investor George Soros, has warned it may slump more than 20 percent in the immediate aftermath of Brexit.

A sustained retreat in the sterling would threaten to reduce cash flows for companies with UK exposure, as they convert the weakening pound at a lower rate to their functional currency like the Hong Kong dollar, said Hannah Li Wai-han, a strategist at UOB Kay Hian (Hong Kong).

"Such exchange losses would eventually translate into pressure on companies' stock valuations and become a drag on their share prices," added Li.

Companies and banks' profitability could also suffer, fueling concern among anxious investors, as Britain's departure is tipped to have a negative impact on the country's economy structurally. It could cast a pall over companies' operations and banks' credit business in UK, noted Fielding Chen Shiyuan, Hong Kong-based Asia economist at Bloomberg Intelligence.

Chen said such negative sentiment would be reflected in their future share prices.

Hong Kong companies, coupled with their Singaporean and Malaysian counterparts, are seen as the hardest-hit across Asia in the aftermath of the Brexit vote, due to their relatively high business exposure in the UK, Nomura Securities said in a report.