The 13 nominees, which would be a full slate to replace the entire Time Warner Cable board, may be presented later on Monday, the source said.

This would be Charter's latest move to try to acquire Time Warner Cable after its offer of $132.50 per share was rejected for being too low in mid-January.

Time Warner Cable's chief executive, Rob Marcus, has said the company is only interested in an offer above $160 per share or in a deal that drives more shareholder value than the company can create on its own.

The one-month window to nominate a new slate expires in mid-February for Time Warner Cable's upcoming annual shareholder meeting, expected in May. The new directors would have to be voted in by shareholders before they would form a new board that could then study Charter's bid for the company.

"If Time Warner Cable management refuses to negotiate on reasonable terms, we believe Charter will likely secure the votes required to win a proxy fight," said Jonathan Chaplin, a research analyst with New Street Telco, in a research note

Representatives from Charter and Time Warner Cable declined to comment.

It was not yet clear whether Charter would raise its bid for Time Warner Cable when it announces the slate. Charter has been considering whether to raise its offer to the low $140s before or after it nominates a slate.

Shares of Time Warner Cable were up 0.3 percent at $135.72 in late trade on Monday.

Charter is also in talks with No. 1 cable provider Comcast about selling the company some of Time Warner Cable's markets such as New York City, Reuters has reported.

(Reporting by Liana B. Baker; Editing by Lisa Von Ahn and Leslie Adler)

By Liana B. Baker