TOKYO, March 7 (Xinhua) -- Tokyo stocks retreated slightly Wednesday morning as investors digested news that Gary Cohn, chief economic adviser to U.S. President Donald Trump, is stepping down, while also remaining cautious about U.S. protectionists moves.

The 225-issue Nikkei Stock Average lost 40.69 points, or 0.19 percent, from Tuesday to 21,377.07.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, shed 1.00 point, or 0.06 percent, at 1,715.30.

Oil and coal product, iron and steel, and nonferrous metal-linked issues comprised those that declined the most by the morning break.