The European champions triggered the release clause in the Senegalese striker's contract, believed to be £7.5 million, and will now hold discussions with the player over a move
Rumours had surfaced over the festive programme linking Ba with a move to the European champions, and now the Blues have moved to secure his signing.
As a result of the discussions, Ba has been withdrawn from the Magpies' squad to face Everton on Wednesday evening.
"Newcastle United can confirm that Chelsea Football Club has made an official offer for Demba Ba which has triggered the release clause in the player's contract," read a statement on the club’s official website.
"The club has given the player permission to speak to Chelsea FC and therefore he will not be included in the squad for tonight's game against Everton."
Ba – who joined the Magpies from West Ham on a free transfer in June 2011 - has scored 13 goals this season, almost twice as many as Fernando Torres, who has seven.