The Commerce Department proposed this week that U.S. companies owned by foreigners be required to submit annual financial statements to the government.

The regulation would apply to approximately 1,500 firms with assets, annual sales or net income over $5 million a year and in which aliens living outside the United States have a 10 percent or more interest. Most of these are U.S. affiliates of foreign-owned firms. However, companies owning more than 200 acres of U.S. land would be obliged to file, regardless of the property's value.

Both publicly and privately held companies would be required to answer questions about their income, wages and employment or face civil or criminal penalities. No identifying information will be released, according to the International Investment Division of the Commerce Department's Bureau of Economic Analysis.

Yet director George Kruer admits the true owners may never be known if they wish to stay hidden because U.S. authority to register does not go beyond the "first layer" of dummy foreign corporations.

The purpose of the reporting is to measure the extent of existing direct foreign investment in the United States. Periodic surveys of new investment are made by Commerce's Office of Foreign Investment in the United States. This office, however, relies only on public information.

Last year this survey identified 300 completed transactions involving approximately $3.8 billion in foreign capital. This compares with 198 transactions completed in 1976 with an estimated $2.1 billion from abroad. The bulk of the funds went into the manufacturing sector, but the 1977 figures includes a considerable number of commercial real estate transactions.

The Conference Board, a private business research group in New York, reported a record number of 81 foreign investments in American industry during the first quarter of 1978. The leaders were Britain and West Germany. The most sought-after investments were acquisitions of U.S. firms, the most popular being industrial machinery, chemicals, soft drinks and publications!

The provision calling for mandatory disclosure of ownership of 200 or more acres was promoted by the furor that has erupted over alien takeovers of America's farmland.

The General Accounting Office currently is studying state land registration procedures at the request of the Agriculture Department as a possible prelude to some type of federal monitoring, should Congress order it.