Japan Post will not be able to develop a new computer system by October 2007 when Junichiro Koizumi, prime minister, has pledged to split it up into four separate units in preparation for full privatisation, according to its president.

“We cannot do it. It’s such a gigantic business,” Masaharu Ikuta, president of Japan Post, said, referring to the world’s biggest savings institution. The post office has more than $3,000bn in deposits, 280,000 employees and 24,000 branches.