Ryan Kavanaugh, chief executive of Relativity Media, told the magazine that the initial letter "makes my blood boil".
"As the grandson of Holocaust survivors, I know that anyone calling what's going on in Israel 'genocide' versus self-defence is either ignorant and shouldn't be commenting, or is truly anti-Semitic," he added.
Mr Kavanaugh claimed that in the 24 hours after making these comments earlier in the week, he had received more than 500 calls, emails and texts of support, including messages from high-ranking industry executives.
Many of Hollywood's actors have thrown in their two-penneth on the subject, with Jon Voight writing his own open letter declaring that Ms Cruz and Mr Bardem should "hang your heads in shame" for adding to the "fire of anti-Semitism that is raging all over the world".
Despite his condemnation of the pair, Mr Voight does not believe the couple's careers should suffer, saying: "Don't create a blacklist".
Similarly, one industry executive said the Hollywood couple's actions did not reach the "Mel Gibson threshold," referencing the widespread public outrage that erupted after Mr Gibson was caught making an anti-Semitic tirade while being arrested in 2006.
One producer who has previously worked with Ms Cruz, told the magazine that he privately vowed never to work with the actress again.
But another producer said the issue should not affect the couple's careers: "I think the thing any executive or producer will try to calculate before working with Penelope Cruz or Javier Bardem in the near future is what their value is in the all-important international marketplace, and what territories they might have alienated people in by what they said.
"It might not be that many. But it's really all about business," they added.
Both Ms Cruz and Mr Bardem's representatives declined to comment.
- Independent