LONDON (Reuters) -Britain's unemployment rate was 4.2% in the three months to August, unchanged from the three months to July, the Office for National Statistics said on Tuesday, citing a new adjusted estimate.

The experimental figures included new data sources to help compensate for a falling response rate to the ONS' usual Labour Force Survey of households, which usually forms the basis of Britain's job market statistics.

Under the previous set of data, the unemployment rate had been reported as 4.3% for the three months to July.

The ONS also reported a drop in employment of 82,000 during the three months to August under the new methodology. It fell by 133,000 in the three months to July, compared with an earlier estimate of 207,000.

(Reporting by Andy BruceEditing by William Schomberg and Paul Sandle)