The German postal operator already runs an international mail business in the UK but has been trying to break the lucrative domestic business mail market for some time.
The acquisition gives Deutsche Post, seen as one of the main rivals for Royal Mail's business, a second licence to compete with the monopoly provider. The Germany company will also gain a delivery network straight to businesses in London bypassing Royal Mail's own network.
A spokesperson for Deutsche Post said that it hopes to roll out the Speedmail concept across the UK and merge it with its own operations.
Speedmail delivers more than 12m items of business mail each year in London and is one of the biggest competitors of the state-owned incumbent Royal Mail. The group, which employs about 110 staff, also offers virtual mailroom services.
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