(Reuters) -The European Union criticised Russia on Saturday for putting subsidiaries of one Italian and one German company under the "temporary external management" of a Gazprom entity, saying the move underscored Moscow's disregard for international norms.

Russian President Vladimir Putin placed the Russian subsidiaries of Italian water heating company Ariston and German appliance maker BSH Hausgeraete under JSC Gazprom Household Systems, according to a decree published on Friday.

"These measures, targeting legitimate economic activities, are yet another proof of Russia's disregard for international law and rules," a spokesperson for the EU's diplomatic service said in a statement.

It said the moves confirmed that Russia, which is waging war on Ukraine, was "an unpredictable actor also in the economic field, and has created a business climate which is arbitrary and hostile towards foreign investors".

"The European Union calls on Russia to reverse these measures and seek acceptable solutions with European companies targeted by them," the statement said.

Ariston said on Saturday it was "extremely surprised" by the move and was assessing the implications of the decree from a governance and managerial standpoint.

(Reporting by Andrew Gray in Brussels and Rishabh Jaiswal in Bengaluru; Editing by Hugh Lawson and Timothy Heirtage)