The United States may soon have to consider limits on foreign ownership of American companies to regain the level of economic independence "which we have lost in this decade," New York investment banker Felix Rohatyn said last night.

In a speech to the Economic Club of Washington, the Lazard Freres partner painted a grim picture of declining U.S. economic power at a time when Japan and West Germany are in the ascendancy.

He said that American dependence on foreign capital raises a serious security question, saying there could come a time when it may not be in Japan's interest to support U.S. economic growth, as it does now, or when it may not be in Europe's interest to share in our defense burden.

Although Rohatyn acknowledged that "it is heretical to even suggest that some limitation on freedom and trade might be considered," he said the United States may have to consider such limits unless there is an improvement in the nation's financial condition or some basic changes by Japan and West Germany that reduce U.S. dependence on them.

He said the decline of the dollar and rise in the yen, coupled with a soaring Tokyo stock market, has given Fuji Bank a current market value of about $60 billion, or 10 times the value of the Morgan Guaranty Trust Co. Similarly, the Toyota company is worth about $40 billion, compared with Chrysler's $4 billion.

"It does not require a great leap of the imagination to see Japanese companies ... able to acquire controlling interests in major American companies at relatively small cost to themselves in relation to their own equity values.

"No major industrial power in the world, certainly not Japan, not even Great Britain, allows foreign control of major strategic companies to be acquired without government approval," Rohatyn said.

In testimony Monday before the House Energy and Commerce Committee, Harvard professor Robert B. Reich urged legislation to limit foreign takeovers, which he said are generally unhealthy for the economy. Reich's views, similar to Rohatyn's, were challenged in other testimony by Texas oilman and corporate raider T. Boone Pickens Jr.

Rohatyn told a reporter that he could not cite a specific case in which a foreign investor had gained controlling interest in an American company.

But he argued it would be logical to extend the review mechanism that now exists for acquisition of defense-related companies "to other sensitive areas."

Citing Sony Corp.'s recent $2 billion purchase of CBS Records, he asked: "Should we allow Sony to acquire control of Time Inc. ... ? Would we allow purchase of foreign control of Morgan Bank?"

In an interview, Rohatyn said he had only lately come to question the desirability of complete freedom for foreign investment capital in view "of our growing dependence" on money from abroad.

He stressed that he is not proposing actual limits on investment, "but at least we should consider a review process, and find out what their intentions are" when foreigners offer to buy into a company or bank.

On the trade side, he contended that the 50 percent devaluation of the dollar orchestrated by the Reagan administration is just as protectionist in intent as restrictive trade rules, adding:

"It is by no means certain that temporarily limiting the foreign shares of certain of our main markets to reasonable percentages, by administrative means, might not be preferable to further significant dollar devaluation, if such temporary restrictions were coupled with important domestic investment commitments and vigorous cost control."

Rohatyn said in the speech that Japan, West Germany and others could help preserve American commitments to freedom of trade and investment by specific actions, in addition to reciprocal open trade and investment practices of their own.

The first requirement, he urged, would be for them to pick up at least a 50 percent share of the global defense burden, whose cost "will obviously go up significantly with the depreciation of the dollar."

Beyond that, he said Japan, West Germany and other surplus countries "should agree to take the lion's share" of the Third World's needs for new capital by being the major providers in capital increases for the World Bank.

When such steps have been taken, Rohatyn suggested, another Bretton Woods conference should be called to agree on predictable, but not necessarily fixed, relationships among the dollar, yen and European currencies.

"An undervalued dollar is neither a symbol of strength nor an unmixed economic blessing," he said.

To achieve stabilization, however, "requires a willingness to coordinate fiscal and monetary policies multinationally, as well as the capacity on the part of national banks to intervene massively," the New York investment banker said.