Is There Really a Feud Between Diane Sawyer and Katie Couric?

INSIDE EDITION speaks with the author of The News Sorority who has some people asking if there’s an ongoing feud between Diane Sawyer and Katie Couric.

Katie Couric versus Diane Sawyer was reputed to be one of television's most cut-throat rivalries.

But how vicious was it, really?

A new book, The News Sorority written by Sheila Weller, takes an in-depth look at the careers of Couric, Sawyer and CNN's Christiane Amanpour.

"When you think of women who broke the glass ceiling in TV broadcasting, you think of Sawyer, Couric and Amanpour," says Weller.

See More Of Weller's Interview With INSIDE EDITION

All three faced tough obstacles at the start of their careers.

Couric started out at local news in Washington.

"She was called perky. She was called a lightweight. She was incredibly ambitious. She believed in herself, and she wouldn't take no for an answer," describes Weller.

Sawyer started out as a Junior Miss from Kentucky. She became a press aide to President Nixon and then went to work for CBS.

INSIDE EDITION's Steven Fabian asks, "You point out in the book that Dan Rather was against her coming on board at CBS?"

Weller explains, "Everybody at the bureau was against her. The whole crew of A-list Watergate sleuths said 'Are you kidding? A Nixon loyalist coming in, and besides, she was a beauty queen?'"

Both women were gunning for the same dream - to become the first female to solo anchor an Evening News broadcast.

Couric won that round in 2006 when she was named CBS Evening News Anchor.

"Sawyer kinda gulped. She wasn't pleased by it," said Weller.

Weller, a well-respected writer for Vanity Fair, says Sawyer lobbied hard to replace Charlie Gibson on World News Tonight.

She quotes a source at ABC as saying, "In the summer of 2009 Charlie had lost his momentum and Diane moved in for the kill."

Weller insists, "She pushed for that. You know, It was kind of her time, it was kind of her turn."

Sawyer ended up at the anchor desk for five years before stepping down last month.

Couric's talk show was cancelled after a two-year run due to low ratings. She's now at yahoo.com.

Despite their intense rivalry, Weller says that Couric and Sawyer actually have a lot of respect for each other.

Weller explains, "They did Philanthropy together. They were at events together. After hours they were totally fine."