Giuliana Rancic’s exit from “E! News” has been “in the works for some time,” but the final straw was when the network hired her archrival Maria Menounos, according to an insider.

“It’s the battle of the bitches. They’re like oil and water. They cannot stand each other,” says the source.

The strife between them goes back even before Maria’s E! days.

“They’ve always been rivals. Maria sees Giuliana as competition and it goes back years,” our source said. “They never speak and they won’t appear on-set together. It’s kind of unspoken that if she is in the building, Giuliana wants nothing to do with her.”

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Another source insisted, “Maria doesn’t have any issues with Giuliana, she sees her as a role model. Giuliana doesn’t feel the same way.”

Rancic’s E! exit strategy involves developing and hosting other TV shows. In 2013, she hosted “Ready for Love” with her husband Bill Rancic, produced by Eva Longoria. The ratings were so low, NBC pulled it from the schedule and released the rest of the episodes online. The ratings for “E! News” also haven’t been stellar.

“Giuliana knows it’s a sinking ship and she’s had an awful year. It’s half her decision to leave and half getting pushed out,” we’re told.

Rancic will stay on for “Fashion Police” and “Live From the Red Carpet,” but we hear there will be more changes at “E! News.” Correspondents Alicia Quarles, Jesse Giddings and host Terrence Jenkins are on their way out. Ali Fedotowsky said she was leaving earlier this month.

Our insider told us the hour-long show will be trimmed to 30 minutes and will be more of a “live chat show” hosted by Menounos.

A show rep denied it, saying, “This is completely untrue and what you’re hearing is totally false. ‘E! News’ remains an hour news show that covers pop culture and entertainment.” Reps for Rancic did not get back to us. A rep for Menounos couldn’t be reached.

This article originally appeared in the New York Post.