Germany's biggest telecoms company is to follow Vodafone in disclosing for the first time the number of surveillance requests it receives from governments around the world.

Deutsche Telekom, which owns half of Britain's EE mobile network and operates in 14 countries including the US, Spain and Poland, has already published surveillance data for its home nation – one of the countries that have reacted most angrily to the Edward Snowden revelations. In the wake of Vodafone's disclosures, first published in the Guardian on Friday, it announced that it would extend its disclosures to every other market where it operates and where it is legal.

A spokeswoman for Deutsche Telekom, which has 140 million customers worldwide, said: "Deutsche Telekom has initially focused on Germany when it comes to disclosure of government requests. We are currently checking if and to what extent our national companies can disclose information. We intend to publish something similar to Vodafone."

Bosses of the world's biggest mobile networks, many of which have headquarters in Europe, are gathering for an industry conference in Shanghai this weekend, and the debate is expected to centre on whether they should join Deutsche and Vodafone in using transparency to push back against the use of their technology for government surveillance.

Mobile companies, unlike social networks, cannot operate without a government-issued licence, and have previously been reluctant to discuss the extent of their cooperation with national security and law enforcement agencies.

But Vodafone broke cover on Friday by confirming that in around half a dozen of the markets in which it operates, governments in Europe and outside have installed their own secret listening equipment on its network and those of other operators.

Under this direct access system, wires suck up traffic at key points in the network, allowing unfettered access to the content of phone conversations and text messages, and in some cases delivering live data about the location of customers.

They allow surveillance without the usual warrants, and it means the phone company cannot know how many people are being targeted and what the justification is for any snooping.

Vodafone will formally table its Law Enforcement Disclosure report, which sets out country by country the laws that oblige it to help governments spy on citizens, at the GSMA industry group conference in Shanghai.

Disclosure may pose a dilemma for Orange, formerly France Telecom. Like Deutsche it is still partially state-owned, and French newspaper Le Monde reported this year that the company had deep links with its domestic intelligence agency.

A spokesperson for Orange said: "Orange respects the laws and regulations of every country in which it is present. Naturally, this means that the group rigorously adheres to the legal framework with regards to all surveillance requests emanating from state authorities across its footprint."

The newspaper confirmed, using files obtained by Snowden, that Orange had collaborated with the Direction Générale de la Sécurité Extérieure (DGSE) to break encryption codes, and that the agency was allowed free and total access to all traffic on its network.

Campaign group Access asked Orange at its annual meeting this year to begin publishing data on warrant numbers, and has called on all operators to do so. The biggest European companies, including Spain's Telefónica, Portugal Telecom and Telecom Italia, operate in many of the same markets for which Vodafone has published its numbers.

"Working together, operators can make a clear stand against unfettered surveillance," said Access policy counsel Peter Micek. "Competition on transparency is something we would welcome. It's not going to happen overnight, but I think Vodafone has made a great headstart for the sector and it is incumbent on the rest of the field to follow up quickly."

"Europe has a strong charter of fundamental rights, and those rights apply online as they do offline. There is a strong basis for Europe to act in a concernted manner to end practices like direct access."