Swiss national Juerg Buergin who was jailed last week for obtaining commercial sex from an underage escort filed a notice of appeal against his conviction on Monday.

The 41-year-old former bank executive director was found guilty last month after a four-day trial of two counts of paying $600 and $650 for the sexual services of the minor at luxury hotels on Sept 29, 2010 and Jan 3, 2011 respectively.

He was sentenced to four months and three weeks in jail by District Judge Eddy Tham on Wednesday.

The father of two was the first among 51 men to have claimed trial for commercial sex with the minor.

Before Buergin, 18 men had been sentenced to between eight and 16 weeks' jail for similarly having paid sex with the escort.

Buergin's lawyer Selva K. Naidu said his client, who is currently serving his jail term at Admiralty West Prison, is not appealing against the sentence.

The maximum punishment for the offence is seven years' jail and a fine on each charge.