The move by the telecoms giant raised eyebrows in Europe's biggest economy, which is led by Forbes magazine's "most powerful woman in the world" Angela Merkel, but marred by a thick 'glass ceiling' in the workplace.
German women earned 23.2 percent less per hour than their male colleagues in 2008, according to the Federal Statistics Office (Destatis), meaning each would need to toil about three months longer per year to get equal pay.
In the European Union, the average rate is 18 percent. Only Estonia, the Czech Republic, Austria and the Netherlands are doing worse on fair compensation for women.
Italy has the smallest gap in pay for men and women in the 27-nation bloc at 4.9 percent, versus 8.5 percent in Slovenia, 9.0 percent in Belgium and Romania and 9.2 percent in Malta. Britain showed a 21.4-percent gap.
Beyond anti-discriminatory measures introduced at the EU level, the then centre-left government of Germany in 2001 adopted a handful of cooperative steps with industry to address the problem.
"But only on a voluntary basis" and with little impact, said Katharina Pühl, a gender studies researcher at Berlin's Free University.
"Since 2001, pay differences for men and women have not fallen significantly, neither for executive positions nor in general," added Anne Busch of the DIW economic institute.
Four years later, Germany elected its first female chancellor, but German women have seen little sign of a "Merkel bonus" in the workplace.
A DIW study published this month found the gulf in compensation even wider - 28 percent - when examined for senior positions in the private sector alone.
"The problem is cultural - the stereotypes are very deep-rooted, such as the idea that women must raise the children and men should put food on the table," Pühl said. "It's different in France or Scandinavia."
As a result of family expectations, women in Germany frequently avoid fast-track careers in favour of more child-friendly vocations. But that phenomenon only explains part of the problem, economists say.
Even in comparable jobs and careers, women earn less.
European Justice Commissioner Viviane Reding said this month that the German situation was "unacceptable" as the country is "one of the most developed in the world on the economic level and should provide a good example."
The debate about equal pay and the introduction of Frauenquoten (quotas for women) grew more fervent in the 1990s following national reunification because women had enjoyed more equality in communist East Germany than in the West.
But concrete measures like those of Deutsche Telekom remain a rarity.
The company said March 15 that women would fill 30 percent of its senior positions by the end of 2015, reasoning that the group would operate better with more diversity among its managers.
It was the first company listed on Germany's DAX index of blue-chip stocks to take such a stand.
Industrial giant Siemens is the only DAX company to have a woman on its senior board.
In the face of corporate reticence, many women have called for a law to bring discriminators to heel.
"Real progress will only come if the law books are modernised with punitive measures," said Heide Pfarr of the Düsseldorf-based Economic and Social Science Institute (WSI).
Norway has already passed a law to ensure more women have access to senior positions, and France and the Netherlands are mulling similar legislation.
Since 2006, Germany has had a general anti-discrimination law.
"But it is hard to prove that a pay gap is only linked to gender – other factors often come into play," said the spokesman of the federal bureau charged with fighting discrimination, Jens Büttner.
Perhaps as a result, the law did not set off a "wave of lawsuits" by women over pay disputes as critics of the measure had warned, he said.