In an effort to prevent potential turmoil that could result from the "millennium bug" computer problem, the government mapped out an action plan Friday urging public and private sectors to immediately take preventive measures.

Because many computer control systems are designed to read only the last two figures for the year in a date sequence, they will likely crash or produce severe errors starting Jan. 1, 2000, unless they are reprogrammed. The expected chaos is also known as the "Year 2000," or Y2K, problem.

The action plan, drawn up at a meeting of the advanced information and telecommunications society promotion headquarters, urges the government to thoroughly inform the public of the computer hazard. It also instructs public and private sectors to take adequate measures, particularly in such primary fields as financial system, energy, transportation, health care, and information and telecommunications.

The meeting was presided over by Prime Minister Keizo Obuchi. Meanwhile, the Federation of Bankers Associations of Japan has instructed its member banks to start overhauling their computer systems in December to prevent the potential financial disorder, officials at the Ministry of International Trade and Industry said.

The officials pointed out the need for vendors of computers, software and microcomputer-equipped machinery to disclose information worldwide indicating whether their products are Y2K-compliant to avoid lawsuits.

By June 1999, government offices are to complete trial runs required to avert troubles on computer systems that the public may experience, according to the plan. The plan also stresses the need to support small and medium-size businesses that are being hit hard by the prolonged economic slump and credit tightening.