Two longshoremen's unions will stage a 24-hour strike at the country's major ports on Nov. 21 to protest a recent settlement with the United States over cargo handling at Japanese harbors, union leaders said Tuesday.

It is expected that the strike, planned by the National Council of Dockworkers' Unions of Japan (Zenkoku Kowan) and the All Japan Dockworkers' Union (Kowan Domei), will stop virtually all work at more than 50 of the country's 95 cargo-handling ports.

The unions are demanding that recent agreements the Transport Ministry made with three port trade associations to improve the country's harbor services be scrapped. In particular, the agreements are aimed at changing the practice of "prior consultation."

"They (the agreements) are illegal and represent improper intervention by the government in a labor-management agreement," Hiroyuki Nakao, general secretary of Zenkoku Kowan, said. The agreements are subject to the consent of labor unions because the prior consultation system is based on the labor-management accord.

The unions maintain that the ministry should not have taken part in forming any new agreements, and that they have no intention of negotiating with the Japan Harbor Transportation Association, one of the trade groups, under those new agreements. The unions are also opposed to deregulations currently being discussed by a government panel and are calling for a wage hike for longshoremen, Nakao said.

Meanwhile, Japan and the United States have concluded an agreement in which the United States will drop fines imposed on Japanese shipping companies for port calls made at U.S. harbors in October and November, the Transport Ministry said.