Claus Weselsky, who had previously threatened a wave of "massive industrial action" from January 11th, claimed the breakthrough as part of a deal which would see a one-off payment to drivers of 510 euros - an increase on the 390 euros previously offered.
In return, the GDL would drop its demand for the working week to be shortened by two hours, instead settling for a 38-hour week.
The succession of train strikes, alongside a separate dispute by pilots at Lufthansa, severly hampered both domestic and freight travel in Europe's largest economy in the latter part of this year.
After the last round of strikes, Deutsche Bahn estimated lost revenue at around 100 million euros, with Deutsche Bahn chief executive Rüdiger Grube telling the Berliner Zeitung. "A strike can very quickly cost up to 10 million euros a day."
In an official statement, Deutsche Bahn chief personnel officer Ulrich Weber said on Wednesday: "We have averted strikes. As this is just before Christmas it is good news for our customers and employees.
"Now it is up to us all to come together in the New Year and find some reasonable outcomes."
A second train union, the EVGrepresenting more than 17,000 rail workers, agreed to waive until at least January any possible strike action.
However, the deal only applies backdated for 2014 - further negotiations covering 2015 are set for January.