The 32-year-old had been linked with a move away from Stamford Bridge, with his situation thought to mirror that of Frank Lampard, who is set to leave upon the expiration of his current deal at the end of the season.
Following the Blues' 2-1 win over Arsenal on Sunday, Benitez claimed that the announcement of a new contract for Cole is imminent.
"Now the club has an agreement with the player [we are] really pleased. The paperwork has to be done but the agreement is done," Benitez told reporters.
Cole arrived at Chelsea from London rivals Arsenal back in 2006, and he has since made 284 appearances for the club.