Associated British Ports looks set to be the latest big UK company to pass into foreign ownership, with a consortium including investment bank Goldman Sachs offering £2.85bn to take it over.
Ports are following airports in the great British asset sale
As a result of successive sell-offs, large parts of Britain's infrastructure are now owned by companies based elsewhere.
Many of the assets involved were originally state-owned before the wave of privatisations that took place in the 1980s.
What are the latest examples of British companies passing into foreign hands?
Before the AB Ports deal, Spanish building group Ferrovial grabbed headlines when it launched a successful £10.3bn takeover bid for BAA, which runs seven UK airports.
Both of the latest British takeover targets used to be state-owned. AB Ports, which began life as the British Transport Docks Board in 1962, was privatised in 1982 and floated on the stock market a year later.
BAA has its roots in the old British Airports Authority, created in 1966. It was privatised 20 years later.
Ferrovial is not the only Spanish company to take an interest in corporate Britain. Last year, the Abbey banking chain was bought by Santander, while mobile phone group O2 was taken over by Telefonica.
What other sectors of the economy have been affected?
The privatisation of gas, electricity and water in the 1980s also created opportunities for foreign firms to enter the UK market.
London Electricity was one of the first utilities to be snapped up when US firm Entergy bought it in 1996 for £1.3bn ($2.1bn).
However, it sold the company two years later for £1.9bn to France's EDF, which later bought up two neighbouring power firms and merged them into a new company, EDF Energy.
The capital's water company, Thames Water, has been owned by Germany's RWE since 2001, while Wessex Water passed into Malaysian hands the following year.
RWE also bought Innogy, Npower and Yorkshire Power, while another German company, E.ON, owns gas and electricity company Powergen.
Among other privatised firms, British Steel, which was sold off in 1988, has been part of the Corus Group since 1999, when it merged with a Dutch rival.
Even companies that are not controlled by overseas firms may have a substantial proportion of their shares owned by foreigners. About 35% of all shares in companies listed on the FTSE-100 index are in the hands of non-UK investors.
What are the political implications of all this?
Opening up Britain's state-controlled monopolies to free-market competition was the aim of Margaret Thatcher's Conservatives in the 1980s.
Far from opposing the consequences of this process, Tony Blair's Labour government has defended them.
Mr Blair said earlier this month, in the wake of the BAA announcement, that foreign takeovers of British airports and utility firms should not be a political issue.
He said what was best for UK consumers was a free market with shareholders, not politicians, deciding who was the best management team.
Back in March, Mr Blair defended foreign ownership of utilities, saying: "Liberalised energy markets and more open markets are good for business and for consumers right across Europe."
Does the rest of Europe agree?
Not necessarily. As far as energy is concerned, Britain is arguably in the vanguard of moves by the European Commission to shake up the sector and offer consumers more choice.
But in other areas of economic endeavour, the issue of who is allowed to own key assets has been fraught with controversy - even for governments that profess to abide by free-trade principles.
France's Veolia is one European company with a stake in the British water industry, owning three companies in south-eastern England.
But the French government is happier to let its firms buy assets abroad than it is to allow foreign takeovers of French firms.
Last year, President Jacques Chirac reacted hotly to rumours that US drinks giant Pepsico was poised to bid for food firm Danone.
The bid speculation turned out to be unfounded, but the episode prompted Anglo-Saxon free-marketeers to ridicule France as a country where yogurt was a "strategic" industry.
What about the US? Surely Washington is more "laissez-faire" than the French?
Again, not necessarily - as shown by the row in the US earlier this year over the sale of UK-based ports and shipping group P&O to Dubai Ports World, from the United Arab Emirates.
US politicians mounted a campaign to stop DPW taking control over management at six key US ports, citing security fears.
President George W Bush said their opposition sent a bad signal to Washington's allies. He was backed by economic pundits who said it would give the impression that no Middle East company was allowed to invest in the US.
But it was all to no avail - and DPW eventually had to get rid of its entire US operation in order to placate Congress.
Back in the UK, is there no limit to what Britain will sell to foreign firms?
One possibility which makes UK politicians distinctly uneasy is the prospect that Russia's state-owned Gazprom might enter the UK energy market.
At stake is British Gas, which was privatised in 1986 and is now owned by a company named Centrica.
The deputy chairman of Gazprom's board, Alexander Medvedev, has admitted Centrica is on its list of potential takeover targets.
But Russia's apparent willingness to use energy supplies as a political weapon - as shown by its cutting of gas supplies to Ukraine earlier this year - makes the issue problematic.
Chancellor Gordon Brown has said such a takeover might raise "political issues".
The Conservatives agree, with shadow trade and industry secretary Alan Duncan saying there should be "no question" of Gazprom being able to buy a UK utility without the company's management being decoupled from the Russian government.