BERLIN (Reuters) - German joblessness rose unexpectedly in September on a seasonally adjusted basis, pushing up the unemployment rate slightly although it is still close to its lowest level since reunification more than two decades ago, Labour Office data showed on Tuesday.

The number of people out of work increased by 25,000 to 2.975 million on a seasonally adjusted basis in September, the data showed.

That compared with the consensus forecast in a Reuters poll for a drop of 5,000. The rise overshot even the highest estimate for an increase of 7,000.

The jobless rate crept up to 6.9 percent from 6.8 percent in August.

(Reporting by Annika Breidthardt; Editing by Madeline Chambers)