Agencies run by WPP, the world's second-largest advertising company, are bracing for cuts across the board in January, the paper said, citing sources.

Interpublic is mulling layoffs in the event General Motors Corp slashes its ad spending even further or reduces its stable of car brands, the paper said.

Most of GM's U.S. advertising is handled by units of Interpublic and Publicis Groupe SA.

Several agencies run by Omnicom, the world's largest ad company, have seen job cuts this year, and those agencies are expected to make additional cuts next year, the paper said, citing industry watchers.

Interpublic, Omnicom and WPP could not be immediately reached for comment.

(Reporting by Pratish Narayanan in Bangalore; Editing by Erica Billingham)