Japan has bought another 52,500 tons (45,000 metric tons) of U.S. rice to help make up for a shortfall in its domestic harvest.

Ralph Newman Jr., chairman of the California Rice Industry Association, a grower group, said the shipments would be made in December and January.The first half of a 14,700-ton (13,200-metric-ton) order, which Mr. Newman said Wednesday is the first U.S. rice exported to Japan in nearly two decades, is being loaded aboard a cargo ship this week. The rice is needed, exporters said, because Japan is suffering from its worst harvest since World War II.

"We remain actively engaged in discussions with Japanese officials about additional exports of rice from California and are hopeful that additional sales will be announced soon," Mr. Newman said.

Meanwhile, the Kyodo news agency in Tokyo, citing government officials, said Japan has reached a basic agreement to lift its ban on commercial rice imports by accepting a tariff proposal.

The agency said the agreement had been reached in talks with the United States and that it called on Japan to convert its current ban on commercial rice imports into tariffs after a six-year moratorium.

A spokesman at the agriculture ministry said he did not know of such an agreement or of any new developments on the rice issue.

Kyodo said the agreement required Tokyo to allow minimum access to its rice market - equal to only 4 percent to 8 percent of consumption - during the moratorium.

Japanese importers also are pondering how to sell foreign rice to consumers as its first emergency rice imports arrived from Thailand on Thursday.

A ship carrying 7,000 metric tons of Thai rice docked at the port of Yokohama, the first load of foreign rice to arrive since 1984 when it bought

from South Korea after another poor harvest.

Japan's Food Agency has indicated it plans to mix foreign table rice with domestic rice, but the final decision will likely be left to individual sellers.

Japan also has said it will import 200,000 metric tons of foreign rice this year for processing purposes, from Thailand, the United States and China, but stressed that emergency imports were a one-time-only measure and did not signify weakening of its blanket ban.

Those imports will be followed by a further 900,000 metric tons by March 1994, including high-grade table rice. U.S. sources said that Connell Co. of New Jersey already sold 52,500 tons of the staple to Japan.