No business leader in America has railed more against federal subsidies than J. Peter Grace, chairman and chief executive officer of the $6 billion-a-year conglomerate, W.R. Grace & Co.

His Grace Commission called for 2,478 austerity measures that it says would "stop the excessive and unnecessary squandering of government funds for foolish projects." A commission official says wasteful spending is "sending the country down the tubes for future generations of Americans."

Grace rarely mentions, though, that his company, like most large, diversified corporations in America, is a major beneficiary of federal expenditures in the form of spending subsidies and tax breaks that allowed it to wipe out its 1981 to 1983 tax bill.

Even the waste-fighting Grace Commission cashes in. Grace emphasizes that the commission's money comes from private contributions, but these are mostly tax-deductible, meaning that the U.S. Treasury is a silent partner in each donation. This is because Grace has formed a tax-exempt foundation to solicit the funds, which qualify as charitable contributions in the eyes of the internal revenue code. The Grace company, No. 53 on the Fortune 500 list, is a multinational conglomerate that deals in fertilizer, fast food, chemicals, sporting goods, animal husbandry, petroleum, minerals, hardware and more.

It uses federally subsidized inland waterways to ship millions of tons of fertilizer a year, according to John Gish, a Grace vice president. The government operates the waterways at a cost of $3.5 million a day, while businesses pay a total of $100,000 a day in user fees, according to the Office of Management and Budget.

A major exporter of agricultural products, Grace & Co. benefits, according to Gish, from the Export-Import Bank, which lends money to foreign customers of American firms, and from Public Law 480, which aids developing countries in securing food.

It also uses the Overseas Private Investment Corp., which insures American companies from expropriation in politically unstable settings. A 1977 General Accounting Office study named Grace & Co. as one of three U.S. companies that had received a total of 29 percent of OPIC's insurance at that time.

Grace's agricultural divisions use research data, provided free by the Tennessee Valley Authority, in deciding which products to develop. And they make extensive use of the Freedom of Information Act process to gather at little expense federal data on competitors, according to Gish.

On the tax side of the ledger, Grace wiped out its federal tax bill for the years 1981 to 1983 because of tax breaks available to its divisions and by selling excess tax benefits to other companies, according to the company's 1983 annual report.

Grace earned $684 million in domestic profits in that period, excluding state and local taxes paid, the report shows.

The company's write-offs included $99 million in deductions from purchases of tax-favored equipment; $61.3 million in tax credits for the purchases, for research and development and other investments; $10.7 million in depletion allowances, and lesser breaks. These write-offs reduced the company's 1981-83 tax bill to $40.5 million, or 6 percent of its profits, compared with the 46 percent statutory rate.

The company also made $53.2 million in 1982 by selling "excess" tax benefits, for a net 1981-83 gain of $12.7 million from the tax system. Congress no longer allows such sales, but they were legal, and widely used, at the time.

Gish emphasized in an interview that the company is not endorsing the subsidies by taking advantage of them. In fact, the Grace Commission proposed abolishing most budget subsidies benefiting Grace. For now, though, they are part of the environment in which Grace and its competitors operate, Gish said.

"We have a fiduciary responsibility to our stockholders," Gish said. "If we have an officer who says: 'Here's a federal subsidy, but I'm not going to take it because the government has a deficit and I want to help wipe it out,' that guy should be out in the street. It'd be like Grace writing in its financial statement to the stockholders: Profits are down, but we managed to increase our taxes this year to do our share in trying to reduce the federal deficit."

Grace & Co. has distributed a memo stating that its sale of tax benefits was not a tax break but a transaction that should be viewed as increasing the company's income. It concludes that Grace & Co. had a $40.5 million tax bill for the years 1981 to 1983.

One congressional aide who wrote Grace to inquire about his firm's tax breaks was sent the memo along with a cover letter from Grace that ended:

1.) What's the above to you?

2.) Are you comfortable in the splendor of the Rayburn House Office Building?