London: German engineering giant Siemens will stick with its involvement in the controversial Adani mine project in Queensland despite a backlash from climate activists in Europe and Australia.

Emerging from a board meeting convened to decide whether to abandon a $29 million contract to provide signalling equipment for the coal mine's railway, chief executive officer Joe Kaeser said the company had a "legally binding and enforceable fiduciary responsibility" to carry out the project.

But in a sign of the growing power of the anti-Adani movement in Australia and now Europe, Kaeser said he "may have acted differently" had it been his own private company and moved to invite German climate activists to participate in a new sustainability committee.

"I do realise most of you would have hoped for more," he said in a statement.