MPs will debate later this month whether the US presidential hopeful should be refused entry.
It follows the billionaire property tycoon calling for a temporary ban on Muslims entering the US.
More than half a million people backed a petition calling on the tycoon to be barred for his comments, triggering a debate in the Commons.
However, there will be no vote at the end of the debate and it will be up to Home Secretary Theresa May to decide whether or not Mr Trump should be excluded from the UK.
Mr Trump owns the Turnberry golf course in South Ayrshire as well as Trump International Golf Links near Aberdeen.
In a statement, his Trump Organisation said it had planned to invest more than £200m at Turnberry and a further £500m at the Aberdeenshire course.
But it warned that any action to restrict travel would force it to “immediately end these and all future investments we are currently contemplating in the United Kingdom”.
It added: “Westminster would create a dangerous precedent and send a terrible message to the world that the United Kingdom opposes free speech and has no interest in attracting inward investment.
“This would also alienate the many millions of United States citizens who wholeheartedly support Mr Trump and have made him the forerunner by far in the 2016 presidential election.
“Many people now agree with Mr Trump that there is a serious problem that must be resolved. This can only be achieved if we are willing discuss these tough issues openly and honestly.”
Scottish First Minister Nicola Sturgeon last month joined the calls for Mr Trump to be considered for exclusion from the UK.
Prime Minister David Cameron has previously labelled Mr Trump’s comments “stupid” but said he did not support a ban, telling MPs the tycoon would “unite us all against him” if he visited the UK.