The $250,000 Colgate Series Championship, the final playoff for the top eight singles players and top four doubles teams in the season-long Colgate International Series of women's tennis tournaments, will be played at Capital Centre the first week in January, The Washington Post has learned.

The women's equivalent of the men's Grand Prix Masters Tournament, the Series Championship has been played the last four years at Rancho Mirage, Calif., in November.

It has been moved as part of a rearrangement of the women's tennis calendar, and will be played the week when Washington formerly hosted the opening tournament of the winter tour sponsored first by Virginia Slims and now by Avon Products.

Colgate-Palmolive, sponsor of the men's Grand Prix circuit as well as the women's International Series, originally planned to hold the playoffs for both simultaneously at New York's Madison Square Garden next January.

But Avon, a bitter rival of Colgate in the international cosmetics industry, had scheduled the eight-woman, $300,000 climax of its 11-tournament $2 million winter tour at Madison Square Garden, March 17-23.

Avon executives were adamant that they did not want Colgate encroaching on their showcase by holding a major women's tournament in the same building three months earlier.

A compromise, worked out in lengthy negotiations coordinated by Jerry Diamond, executive director of the Women's Tennis Association, provided that Colgate would give up its plans to hold the Series Championship alongside the men's Masters in New York in exchange for the right to play its finale in Washington the first week of the year. Avon had tentatively planned to open its circuit here that week.

The Avon Circuit will now begin the week of Jan. 8 in Cincinnati, and will continue on successive weeks in Kansas City, Chicago, Seattle, Los Angeles, Oakland, Detroit, Houston, Dallas, Boston and New York.

Contracts for the Series Championship will be signed later this week, it was learned.

The Colgate International Series links approximately 40 tournaments in 10 countries, including Wimbledon and the U.S. Open, with a point system leading to $750,000 in year-end bonus prizes for the top 35 women in singles and top 20 teams in doubles. The top eight singles players and four doubles teams also qualify for the Series Championship.

Ray Benton, a partner in the Washington law firm of Dell, Craighill, Fentross and Benton, is expected to serve as tournament director of the Series Championship. He also directs the Colgate Masters in New York, and headed the Virginia Slims and Avon tournaments here. The tournament will be copromoted by Capital Sports Inc. of New York.

Benton also said yesterday that Volvo of America has renewed its contract to sponsor a $125,000 men's Grand Prix tournament at Smith Center next March.