TOKYO -- Asian companies that regarded the U.K. as a safe foothold in Europe's single market now see a landscape upended by the outcome of Thursday's British referendum.
Hitachi Chairman Hiroaki Nakanishi had joined David Cameron in arguing against a British exit from the European Union, with the prime minister citing the Japanese industrial group's investments as a reason to remain.
Hitachi, which started up a rail car factory in Britain last autumn and hopes to do the same to a nuclear reactor there early next decade, has received approval for both from British authorities. The impending fall of Cameron's government may produce political turmoil that stalls infrastructure construction and impacts the company's U.K. operations. Those contributed 300 billion yen ($2.93 billion), or roughly a third, of Hitachi's European sales in fiscal 2015.
"Re-creating the relationship we have now with a new government will pose a challenge," Nakanishi said in reaction to the referendum outcome.
Nissan Motor, which assembles about 500,000 vehicles a year at its Sunderland plant, competes with Jaguar Land Rover as one of the biggest automakers operating in Britain. President Carlos Ghosn warned before the referendum that an Out vote would force Nissan to rethink future investments in the U.K.
"It would be better to remain," Vice Chairman Toshiyuki Shiga said Thursday, "but we will respect the outcome of the referendum and give thought to our operations as we go."
If the U.K.'s withdrawal from the EU leads trading partners to raise tariffs on British-made goods, worsening the economics of exporting from there, Nissan may shift production or vehicle development to the Continent.
Other Japanese automakers have presences in the U.K. Toyota Motor's local unit has rolled out an annual 190,000 or so cars in recent years, about 75% of which are exported to the European market. Nine out of 10 of the 115,000 cars that Honda Motor produced there in fiscal 2015 were shipped to Europe. Honda intends to ready for British production of a new model while watching how events play out.
For Canon, London is home to headquarters for Europe, Africa and the Middle East -- a business region that produces 1 trillion yen in annual sales, making it as important as Japan or the U.S. Sony has production and business units in the U.K. and takes in nearly a tenth of its sales there.
Japanese financial institutions must also come to terms with the consequences of Brexit.
Sumitomo Mitsui Banking Corp., insurance group Sompo Japan Nipponkoa Holdings and others will consider incorporating new European units outside of Britain.
A major concern raised by a British withdrawal from the EU is the fate of U.K.-based financial institutions' "passports" -- the right to sell services across the single market with only a license from British authorities. This arrangement may become a casualty of the two years of exit negotiations with the EU that lie ahead.
SMBC has opened branches in Paris, Madrid, Milan and other cities on the Continent from a base in London. The Sumitomo Mitsui Financial Group unit's possibilities for coping with Brexit include upgrading a branch in, say, Dusseldorf or Brussels to corporation status and acquiring a new "passport." Sompo Japan described seeking a continental license to offer insurance as an option.
Nomura Holdings, which employed some 2,500 people at its European hub in London as of March 31, may also be forced to relocate staff to the Continent --- possibly Frankfurt or Paris -- if it can no longer use its "passport."
The parent of leading Japanese brokerage Nomura Securities only recently decided to withdraw from stock underwriting and corporate analysis in Europe, areas where it has underperformed. Brexit could force even more cutbacks. Senior Managing Director Steven Ashley has warned of significant negative effects on investment banking and other businesses.
Brexit also poses a challenge for companies elsewhere in Asia with significant exposure to Britain.
Hong Kong billionaire Li Ka-shing's CK Hutchison Holdings is expected to reconsider its bid to acquire O2 UK, the country's second-largest wireless carrier, among other plans. Deputy Chairman Victor Li had suggested this would be a possibility in the event of a British withdrawal from the EU. The U.K. accounts for roughly a third of the group's profit.
Mainland Chinese companies have been investing liberally in the U.K. Shanghai-based developer Greenland Group is staking 1.3 billion pounds ($1.77 billion) on a real estate project, for instance.
Cameron and Chinese President Xi Jinping agreed to expand economic cooperation when the latter visited the U.K. last October, opening the door to Chinese-built nuclear reactors. Such plans may undergo a significant rollback in the wake of Cameron's departure.
Jaguar Land Rover, owned by India's Tata Motors, plans to build an automobile factory in Slovakia to contend with the possibility that post-Brexit tariffs hurt its export competitiveness.
Britain leaving the EU will have a negative effect on London's real estate market, warned Grant Kelley, CEO of Singapore-based City Developments.
On the whole, however, Brexit is expected to have only a limited direct impact on Southeast Asian companies. The same is true for leading South Korean manufacturers, which have no significant production capacity in the U.K. But they still have to reckon with the possibility that it depresses the entire global economy.
Nikkei staff writer Wataru Yoshida in Singapore contributed to this article.