Secrecy on commissions cost Boeing $450,000

The Boeing Company had to face one more difficulty last week: a $400,000 fine and $50,000 in court costs for concealing $7.3 million in commissions it paid to sell airplanes in four countries.

The company admitted in US District Court June 30 that it had not disclosed the payments to the Export-Import Bank, which had financed portions of the sales and thus unknowingly paid some of the secret commissions.

The commissions involved sales of the company's 727-200, 737, 727, and 747 airplanes to Spain, Honduras, Lebanon, and the Dominican Republic. The payments were made between 1973 and 1977. This was before passage of the 1977 Foreign Corrupt Practices Act, so they were not considered illegal. Boeing did fail to reveal them to the Eximbank, however, which financed $143.4 million of the $343. 3 million cost of the 35 airliners.

At the hearing, Thornton Wilson, Boeing's chairman and chief executive officer, appeared with lawyer Edward Bennett Williams and turned over a $450,000 check to the government.

In a statement, Mr. Wilson said ''tightened company policies, procedures, and internal controls have been in place since 1976 to assure that legal and technical requirements such as those posed by the Exim forms are being met.''