ANXIETIES ABOUT foreign investors, and rumors that they are somehow surreptitiously buying control of the country, keep recurring here. There's nothing to them. Foreign ownership has been rising, but it falls far short of control of any significant sector. Investment from abroad, like domestic investment, strengthens the American economy. Rep. Benjamin Rosenthal and his subcommittee continue to see much danger, particularly in Arab investment, and to argue that the statistics are inaccurate. But the subcommittee's research so far has chiefly succeeded in demonstrating--to the satisfaction of most other people, if not its own-- that foreign investment is still small by the gigantic scale of the American economy, and is no threat to its stability or anything else.

Of all the OPEC countries' surpluses--their unspent oil revenues--since the first big price increases eight years ago, it appears that slightly less than one-fifth have come to the United States. That's not an overwhelming proportion. Much more of that money is in Europe. The OPEC surpluses, incidentally, rose to a peak of about $103 billion last year and are now declining. Oil prices have softened, and the exporting countries are spending their incomes faster. The Morgan Guaranty Trust Co., which has been tracking these numbers with great care, estimates that the OPEC surpluses will fall to about $77 billion this year, and perhaps $54 billion next year. The nightmare vision of an accelerating financial steamroller, fueled by oil and steered by Arabs, is a gross distortion.

Kuwait has just bought the Santa Fe International Corp. of California, an oil drilling company, for $2.5 billion. Why not? Americans have bought a lot of Kuwaiti oil over the years, and it's nice to see some of those dollars come home.

Foreign takeovers always touch national sensitivities, and congressional committees quite properly keep an eye on them. But it's useful for Congress, and everybody else, to remember that of all the countries in the world, this one has the broadest interest in maintaining an orderly flow of international investment free of political assaults. American-controlled oil operations abroad represent four times as large an investment as all the foreign-controlled oil companies here. The door has to swing both ways.

That's not only true of the oil industry. Total direct investment by foreigners in American companies by the end of 1980 amounted to $65 billion, the Commerce Department reported recently. Direct investment means that the foreign owner has at least 10 percent of the company's stock--presumably a controlling interest. By contrast, Americans' direct investment abroad was $213 billion, more than three times as much.

Two-thirds of that foreign investment has come from Europe. Next, as you would expect, ranks Canada, and then Japan. All the rest of the world, including OPEC, holds a little over one-tenth of all foreign ownership here. It doesn't deserve to rank very high on your list of things to worry about. The American economy benefits enormously from this exchange of capital. If Americans want other countries to allow them to invest there, they are going to have to set the world's standard of open access here.