Ba, 27, has been left out of the Newcastle squad for Wednesday night's game against Everton and will now enter into negotiations with Rafa Benitez's side.
Agents representing Ba were reported to have held unproductive talks with Chelsea earlier in the week but will meet with the club once again after a formal offer of £7.5 million was made.
"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 club statement.
"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."
The striker will act as competition for Fernando Torres if he does join Chelsea and will replace Daniel Sturridge, who signed for Liverpool on Wednesday in a deal worth a reported £12m.
Newcastle manager Alan Pardew said he is confident the move will go through.
"It's done. He will go to Chelsea with our blessing," Pardew told Sky Sports 1. "He has done fantastic for us and it's not a bad thing, all the uncertainty is now done and we can move on.
"This club is bigger than any player for sure."
Ba signed for Newcastle on a free transfer following West Ham's relegation in 2011 and has scored 29 goals in 54 Premier League appearances for the club.
Though his form dipped in the second half of last season following the signing of his fellow Senegal international Papiss Cisse, only Robin van Persie has scored more than his 13 goals in the 2012-13 campaign.
Ba spent a spell with Watford early in his career before representing Rouen in France, Mouscron in Belgium and Hoffenheim in Germany.
He failed a medical with Stoke City in January 2011 but subsequently joined West Ham from Hoffenheim and scored seven times in 12 appearances.
In fact, since his arrival in English football, only Van Persie and Wayne Rooney have beaten Ba's tally of 36 Premier League goals.