The office said the number of unemployed grew by 4,000 in seasonally adjusted terms to 2.719 million. Analysts polled by Reuters had expected that figure to rise by 10,000.
The seasonally adjusted jobless rate remained stable at 5.9%.
"Unemployment and underemployment did fall in March, but less than usual this month. The economic downturn is therefore still having an impact on the labour market," labour office head Andrea Nahles said.
(Reporting by Miranda Murray, Editing by Rachel More)
