Newcastle United have given Chelsea permission to hold transfer talks with 27-year-old Senegal striker Demba Ba.

“Chelsea have made an official offer for Demba Ba which has triggered the release clause in the player’s contract,” Newcastle said.

Newcastle, who are sixth from bottom in the table, did not give details of the release clause but media reports suggest it is around £7 million.

Ba has been a mainstay in attack for the north-east club since joining from West Ham United on a free transfer in June 2011.

The striker, who previously had spells with Rouen, Mouscron and Hoffenheim, finished the 2011-12 campaign as the club’s top league scorer with 16 goals.

He has continued his free-scoring ways this season, bagging 13 league goals this season.

Chelsea are desperate for back-up in attack for Spanish international Fernando Torres who is the London team’s most-used outfield player this season.

Meanwhile, England forward Daniel Sturridge has joined Liverpool following an injury-interrupted season with the Stamford Bridge club.

The 23-year-old joined Chelsea from Manchester City in 2009 but was unable to impose himself at Stamford Bridge and has been predominantly used as a substitute this season.

“I am humbled and happy to be here,” Sturridge told the Liverpool website.

“(Liverpool manager) Brendan Rodgers said he sees me here for a long time, and I also see myself here for a long time. I’ve not signed here to play for a couple of years and then move on.”