The agency – owned by parent network Hill & Knowlton – told staff it would close its doors late last week.
Two staff members were made redundant and the other was offered a job at H&K but declined.
The decision follows a global review of Blanc & Otus’ offices that led to a decision to close in London. The agency blames the recession.
Blanc & Otus had positioned itself as a consultancy for start-up tech firms in Europe.
The UK office opened in 2002. It was led by London MD Lance Mercereau.