Gov. David C. Treen said he will convene a special legislative session in January to redraw two New Orleans-area congressional districts, which a federal court said were gerrymandered to prevent a black majority.

The 75-page opinion by a three-judge panel Friday gave Louisiana until Jan. 31 to come up with a new plan. Otherwise, the judges said, they might impose their own.

The ruling came in a 1982 lawsuit in which black voters argued that dividing New Orleans' black population between the 1st and 2nd districts minimized the chance of electing a black to Congress.

Treen, Louisiana's first Republican governor since Reconstruction, said through a spokesman late Friday that he at no time opposed the idea of a majority black district.

Implicit in the ruling is the recognition that bloc voting has settled elections in the districts, a notion with pointed political consequences for incumbents Robert L. Livingston, a 1st District Republican, and Democrat Corinne C. (Lindy) Boggs of the 2nd. Both are white.

Boggs said she has "no quarrel" with the order. "I am accustomed to working with all the people of New Orleans," she said.

An aide to Livingston, who has resisted redistricting attempts, said "It's now up to the state's attorneys to read through the decision and find some grounds for appeal."