Paula Zahn has announced that she is to leave CNN after nearly six years with the network.

The 51-year-old will present the last episode of her news discussion show Paula Zahn Now on August 2.

The show’s 8pm slot will be filled by various substitutes until Campbell Brown, who has signed to join CNN in the autumn, takes over in November.

Zahn joined CNN in 2001, spending her first day on air co-anchoring the events of September 11 with Aaron Brown. She moved to the network’s primetime line-up in 2003 to host Paula Zahn Now.

She said: "After 30 years in the business I've worked every day part on the dial, and there really wasn't anything here above and beyond the show that I was doing that would have been new to me. I wish the next team tremendous success. It is really a challenging hour."