EasyJet will start flying four domestic routes to Duesseldorf, Frankfurt, Munich and Stuttgart.
Along with four domestic routes to Duesseldorf, Frankfurt, Munich and Stuttgart, easyJet will also start flying from Tegel to 15 worldwide destinations, including Zurich, Vienna, Paris Charles de Gaulle and holiday destinations including Mallorca, from January 5th.
Speaking to press on Wednesday, Easyjet Europe manager Thomas Haagensen said that his firm was happy "to offer more competition and lower rates, in particular for domestic connections for which there is now only a very limited selection".
Easyjet said that it would operate four new routes within Germany from January 5, 2018.
As is now stands, Lufthansa is having to offer concessions to receive the green light from the European Union with chief executive Carsten Spohr saying the company will buy Niki virtually without take-off and landing slots if necessary. That drove the load factor - a common measure of capacity utilisation - up by 2.6 percentage points to 92.3 per cent.
On a rolling basis for the 12 months ending in November, Easyjet had notched up more than 81.3m passengers on its aircraft.
EasyJet's deal with Air Berlin will cost about £100mln for the current financial year as it will have to lease crewed planes at first for Tegel while it invests in training crews and refitting planes.
JP Morgan lifted its rating on EasyJet's stock to "overweight" from "underweight" and raised its target price to 1,550p from 1,330p, saying it sees a much improved pricing outlook for fiscal year 2018 and estimated profit contributions from 2019 onward on the back of its purchase of Air Berlin slots.