The Woodward & Lothrop department stores lost $6 million last year, the company disclosed in the last public financial statement it had to file after its purchase by shopping center magnate A. Alfred Taubman.

The loss was revealed in documents filed last week with the Securities and Exchange Commission. Although Woodies is now a privately held company, it was required to make public financial data because of its sale to the public last year of $130 million in subordinated notes.

The financial report will be the last filed publicly by Woodies, said Chairman Edwin K. Hoffman.

"From this point on, we are nice and private," he said.

The chain reported sales of $470.4 million for the fiscal year that ended Jan 31, up from $451.3 million in fiscal 1985.

The company last reported a profit in 1983, but Hoffman said the recent losses are the result of the heavy financing costs incurred when Taubman bought out the public shareholders with borrowed money.

Woodward & Lothrop Inc. officials said they are very optimistic about the future of the department stores.

"Things are superb," Hoffman said. "The loss is right on plan . . . We're really in good shape -- superb shape."

Among other things, Hoffman noted, Woodies is spending $20 million to remodel its downtown store completely. The renovation, to be completed in early fall, will make the downtown store a more powerful competitor against the brand-new Hecht Co. store opened last fall at 13th and G streets NW.

According to the newly reported financial data, nearly half of last year's loss was due to a one-time, $2.9 million write-off, taken when the company retired all of its $300 million in debt that was incurred when the retailer was acquired by Taubman.

Without that write-off, the company would have lost $3.1 million -- less than half the $7.1 million loss the company would have reported in the previous year had it been acquired at the beginning of 1984.

The acquisition imposed substantial increases in Woodies' interest, depreciation and amortization expenses. Because the acquisition occurred in September, Woodies actually lost only $1.1 million in the year that ended in January 1985. Had the acquisition occurred at the beginning of the year, the 16-store chain would have lost $7.1 million.