(Corrects to remove quote referring to a phone call between Biden and Putin in bullet point and body of text after NATO official misspoke)

BERLIN (Reuters) - NATO said on Tuesday that acts of sabotage carried out across the military alliance over the past years included threats to plot the murder of industry leaders such as the head of German arms maker Rheinmetall.

Speaking at the European Parliament, NATO's deputy assistant Secretary-General for innovation, hybrid and cyber, James Appathurai, confirmed the threat against Rheinmetall CEO Armin Papperger that had so far only been reported by the media.

He said the campaign of sabotage included the "derailment of trains, acts of arson, attacks on politicians' property, threats to plot to assassinate industry leaders like, publicly, the head of Rheinmetall but there were other plots as well".

In July, CNN reported that a plot to kill Papperger was one of a series of Russian government plans to assassinate defence industry executives across Europe who were supporting Ukraine's war effort. The Kremlin rejected the accusation.

Appathurai said the West had in the past succeeded in stopping Russia from committing acts of sabotage by setting red lines at the highest level, as had been the case when incendiary devices destined for DHL flights were detected in a German warehouse.

"They can be deterred if you identify what your red lines are amongst yourselves and then communicate that effectively, and that doesn't necessarily mean publicly," he said.

He said the West would not accept as normal the current level of sabotage, which NATO describes as at a record high, and that there was a clear recognition amongst allies "that we need to be more robust" in tackling repeated incidents in the Baltic Sea.

Addressing the problem of attribution, Appathurai suggested NATO should become more assertive and not necessarily wait for the end of a police investigation that might go on for six or seven months before taking action.

"In our view, attribution is important, but it cannot be an obstacle to action," he underlined, adding NATO needed to act if there was continuing damage to underwater infrastructure due to shadow fleet ships dragging their anchors for 100 kilometers (62.14 miles) along the ocean.

"$10 trillion worth of economic activity go through undersea cables, four trillion of which goes across the Atlantic," Appathurai warned. "If that is cut off, there is major economic damage."

NATO aims to agree a strategy for tackling hybrid threats before the alliance's The Hague summit at the end of June.

(Reporting by Sabine Siebold; editing by Bart Meijer, Benoit Van Overstraeten, Richard Lough and Kevin Liffey)