FC Barcelona has said that the fee is 19 million euros (£15m).
The Cameroon international midfielder will sign for the next five seasons with a release clause of 80 million euros (£63m)
On Monday he’ll have a medical and then join the rest of the squad for the official team presentation at the Gamper.
Sky soccer pundit Paul Merson said Saturday that Arsenal will miss Song more than they will Van Persie, as it will be easier to replace the goalscorer than the playmaker.
One Arsenal fan said to Here Is The City: 'We know now where we stand - we are a feeder club for Manchester United, Manchester City and Barcelona. It is deperately disappointing to have lost another key player'.
image: © Ronnie Macdonald