Britain is in a lather over foreign stake-building in some of its largest companies and is hinting at moves to block incursions into British Petroleum Co. PLC and two big confectioners.

While the rumblings echo familiar patriotic strains, the government says its concerns are strategic, not protectionist.The BP case, for example, involves the purchase of a major stake in the company by an OPEC member, which could put the interests of British shareholders at risk, critics say.

They argue that the foreign raids on candy makers Rowntree PLC and Cadbury Schweppes PLC are even more of a mismatch because the raiders themselves are protected against takeover reprisals.

In the BP case, Prime Minister Margaret Thatcher's government said the Kuwaiti government's acquisition of a 22 percent stake in the oil giant warranted investigation because the Arab nation belongs to the Organization of Petroleum Exporting Countries.

Britain, the world's fifth-largest oil producer, is not a member of the cartel.

The Conservative government has referred the matter to the Monopolies and Mergers Commission to determine whether the acquisition is in the public interest, Trade Secretary Lord Young said.

The Kuwaiti government's investment office in London maintains that its BP stake is a long-term investment, and considers it has always acted as a model investor in BP.

It bought the stake piecemeal after the British government sold off its remaining 31.5 percent share of BP last fall.

Meanwhile, the Office of Fair Trading, which advises the trade secretary on whether to call in the monopolies commission, is reviewing two Swiss companies' runs on Kit Kat-maker Rowntree.

Noting that Swiss law protects Nestle SA And Jacobs Suchard SA from takeovers, critics object to the lack of reciprocity.

Kenneth Clarke, secretary of state for trade and industry, said in response to a question in the House of Commons on Tuesday that reciprocity would be a key issue in the review.

The points (being) made about fairness are crucial, Mr. Clarke said.

John Banham, director general of the Confederation of British Industry, Britain's largest industry group, added: We can't safely continue to play football against teams which have built brick walls against their own goals and expect to win.

Swiss food giant Nestle has launched a 2.1 billion ($3.95 billion) takeover offer for Rowntree and has bought an 11 percent stake in the company. Jacobs Suchard has purchased a 29.9 percent holding in Rowntree, the maximum allowed under British takeover regulations short of a full takeover bid.

Also at issue is General Cinema Corp.'s purchase of a 17.7 percent stake in Cadbury Schweppes. The government said Tuesday it would not go to the monopolies commission, but warned that Chestnut Hill, Mass.-based General Cinema could face further scrutiny if it goes ahead with plans to increase its stake.

Critics complain that General Cinema also is bid-proof because some of its shareholders have limited voting rights and the state of Delaware, where the company is incorporated, has passed anti-takeover legislation.

Lord Young denied that the government was becoming protectionist, telling the Observer newspaper: If we start getting into protectionism, we will be the ones to suffer most.

While Mrs. Thatcher is a staunch advocate of free market policies and Britain is an enthusiastic foreign investor, it remains generally resistant to foreign investment.

This company is a national asset, former Rowntree Chairman Sir Donald Barron told applauding shareholders at their annual meeting late last month. It is wrong that it should go to some inanimate place without tradition.