THE EXECUTIVE vice-president of a Japanese firm that has since wound up its operations following trading losses of around US$81 million was sentenced to 36 months' jail on Thursday.

Takahashi Masatsugu, 51, dressed in a dark suit, appeared calm when the sentence was handed down.

He pleaded guilty last month to all 20 charges for his part in aiding a scam that saw Noriyuki Yamazaki, his colleague then at Singapore-based Mitsui Oil (Asia), report inaccurate prices of naphtha, a petrol-based product.

The cover-up surfaced in 2006, when Mitsui in Japan conducted its own investigations after discovering trading losses.

The false price information entered on a spreadsheet helped disguise huge losses that Yamazaki, 37, had run up in his trading.

Takahashi was not Yamazaki's direct superior, but he was in charge of two departments in Mitsui Oil (Asia), the middle office and back office.

Takahashi was accused of giving handwritten instructions to alter profit and loss figures in the daily report, such that the naphtha loss figure was under-reported.

Mitsui Oil (Asia) - which at that time accounted for about half of naphtha trading here - has since been liquidated.

Yamazaki, who pleaded guilty in February, was jailed for five years, while Takayoshi Wada, 46, who was Yamazaki's boss, was sentenced to 20 weeks' jail.