BERLIN (Reuters) - Porsche AG staff at the German carmaker's site in Stuttgart will join a wave of strikes in key German industries on Tuesday, said IG Metall union's local branch, as part of national action planned to push for higher pay.

The strikes will begin from 2 am (0100 GMT) on Tuesday with the night shift at the Zuffenhausen plant, said the IG Metall Stuttgart branch in a statement, with a public rally planned to start 30 minutes later in front of the Porsche Museum.

The Porsche staff join workers in Germany's electrical engineering and metal industries who will launch strikes on Tuesday to put pressure on employers to increase their pay, according to a statement from the IG Metall union.

Tuesday marks the end of a truce period accompanying collective bargaining talks for a proposed pay rise for almost 4 million workers in key sectors covered by the negotiations.

The strikes come as the conflict between Volkswagen workers and the group's management escalated earlier Monday, with the works council saying the carmaker plans to shut three factories in Germany and shrink its remaining plants there, as well as lay off tens of thousands of staff.

Porsche, majority owned by Volkswagen, last week said that it was paring back its dealership network in China to reflect weak demand and also flagged billions of euros in cost cuts.

(Writing by Miranda Murray, Editing by Rachel More)