A federal judge yesterday ordered a special aldermanic election next March in seven redrawn Chicago wards. It could shift control of the city council to Mayor Harold Washington (D) from his white opponents in the city's Democratic organization.

U.S. District Court Judge Charles Norgle followed his earlier approval of the new ward lines, which enhance black and Hispanic voting strength, with an order for a special election March 18, the date of the Illinois primary. The next regularly scheduled city elections are not until the spring of 1987.

Norgle said he had ordered the voting because "there has been no fair aldermanic or committeeman elections in these wards since 1981," the year that the old lines were set.

The new map gives Hispanics, who now hold only one seat on the 50-member council, majorities in four wards and increases black percentages in three other wards, all of which now have white aldermen.

Washington, who cheered the decision, called it "another nail in the coffin of machine politics." But many observers said the main effect would be to increase the political leverage of the city's Hispanics, who could become the swing bloc on the new council.

Since his election in 1983 as Chicago's first black mayor, Washington has found himself on the short end of a 21-to-29 split in the council. The majority bloc, led by Alderman Edward Vrdolyak, the Cook County Democratic chairman, has fought Washington's budget and policy proposals and blocked more than 50 of his appointments.

The new lines have forced one veteran majority-bloc alderman into an announced retirement and put three other Vrdolyak allies into such untenable positions that they are running for other offices in 1986.

According to an analysis by The Chicago Tribune, there are three wards with majority-bloc white aldermen that now will have black majorities: of more than 90 percent, in one instance, 77 percent in another and just over 50 percent in a third. At least two of the three are expected to elect supporters of the mayor. Another Washington ally, a Hispanic ward committeeman, is favored in a ward where the incumbent has been slated for another office.

The most critical battlegrounds may be two other wards with increased Hispanic majorities. Neither of the pro-Vrdolyak incumbents is running, but in one of them Vrdolyak is trying to recruit a popular Mexican-American state representative who has quarreled with Washington.

The seventh ward with new boundaries is the one with the only Hispanic incumbent, Miguel Santiago. Santiago has been voting with Vrdolyak -- underlining the point made yesterday by several observers that Hispanic politicians and voters are the new swing group in Chicago politics.

"They're the group that everyone is courting," said Joe Pecore, a spokesman for former Mayor Jane Byrne (D), an announced candidate for the 1987 contest.

Alderman Roman Pucinski (D), a Vrdolyak lieutenant, said: "The four Hispanic aldermen [expected to win with the new lines] are not going to be rubber-stamps for the mayor . . . . They could be the tie-breakers. This is the dawn of a new era for Hispanics in Chicago."

The lawsuit challenging the ward lines was filed in 1982 by groups representing blacks and Hispanics. Washington supported the move and, when it became clear that the suit was likely to be successful, Vrdolyak joined in drawing the new lines. The compromise plan drawn by the contending forces was approved by Judge Norgle last Friday.

The special election is viewed by Chicago observers as a preview of the 1987 mayoral battle, with major gains possible for Washington if he is able to establish control of the council, but even greater risks if he fails. Vrdolyak's group is considered certain to challenge Washington in 1987, believing that if he is reelected the dominance of the old Democratic organization would be at an end.