March 20 (Reuters) - CBS News will lay off about 6% of its workforce, according to a source familiar with the matter, in the latest move under new Editor-In-Chief Bari Weiss to revamp the network and boost its ratings to catch up with rivals ABC and NBC.

"It's no secret that the news business is changing radically, and that we need to change along with it," according to a memo sent on Friday to employees by Weiss and CBS News President Tom Cibrowski, which was seen by Reuters.

It was not immediately clear which business units or shows were affected by the layoffs.

High-profile journalists such as "60 Minutes" correspondent Anderson Cooper have parted ways with CBS News since Weiss took over as the network's new editor-in-chief in October, following Paramount Skydance's ( PSKY ) purchase of her outlet The Free Press.

Weiss is looking to revamp the newsroom and bring on a "streaming mentality" to the network. She unveiled her strategy in January to add 19 new contributors while focusing on restructuring operations and starting news coverage on digital platforms.

Employees who are affected by the latest layoffs are expected to be notified by the end of the day, the memo said.

"New audiences are burgeoning in new places, and we are pressing forward with ambitious plans to grow and invest so that we can be there for them... parts of our newsroom must get smaller to make room for the things we must build to remain competitive," the memo said.

Variety first reported the news on the workforce reduction.

(Reporting by Harshita Mary Varghese in Bengaluru; Editing by Devika Syamnath)