December 23, 1983

A Pentagon inquiry into the bombing of the Marine compound in Beirut on Oct. 23 has concluded that serious failures in the Marine chain of command contributed to the tragedy, according to Reagan Administration officials. One official said that ''generals and admirals'' in the European Command were included in the ''sharp criticism.'' (Page A1, Col. 6.) The U.S. Marines and French troops in Beirut were warned in an anonymous telephone call to leave Lebanon within 10 days or face a major attack. The caller said he represented a Moslem terrorist group. (A8:1-2.)

Plans for a 93-acre Westway State Park to run along the Hudson River from Battery Park City to 34th Street were announced yesterday by state officials. The park, with plazas, esplanades, playing fields, lawn areas and benches overlooking the waterfront, would be built over the proposed underground highway. State Transportation Commissioner James L. Larocca and State Parks and Recreation Commissioner Orin Lehman announced three alternative designs for the park. They will be reviewed in the next few months by community and park groups, and a final design will be drawn up.

''The Christmas message in Harlem, the good news to the poor, is that 'you're not going to be poor anymore.'

The Securities and Exchange Commission today approved on a 4-to-0 vote an accounting device to let companies dress up their financial condition and show higher earnings by wiping long- term debt off their balance sheets. The device, called in-substance corporate defeasance, allows companies to buy Government securities to reduce their balance sheet debt by an equal amount. Analysts said the technique would appeal primarily to companies with cash to spare and a lot of low-interest debt on their books.

For weeks, if not months, Spaniards have been waiting breathlessly for the arrival of ''El Gordo'' - ''The Fat One.'' And they are not talking about Santa Claus. Today, at 9:21 A.M., El Gordo arrived, a bit earlier than usual. There was the customary pandemonium: flashes from the photographers' lights, cheers and cries, a mad dash for the telephones. Throughout the country people who had gathered around television screens dipped into their wallets and purses and held up bits of paper, re-examining numbers already memorized.