Tokyo stocks opened marginally lower Wednesday as unilateral protectionist moves by the U.S. sparked concerns over a potential widespread trade war.

As of 9:15 a.m., the 225-issue Nikkei Stock Average shed 26.59 points, or 0.12 percent, from Tuesday to 22,512.95.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, edged down 1.99 points, or 0.11 percent, at 1,772.97.

Electric power and gas, and pharmaceutical-related issues comprised those that declined the most in the opening minutes after the morning bell.