Tony Iommi thinks his cancer treatment unintentionally forced Bill Ward to leave Black Sabbath.

Tony Iommi

Tony Iommi

The 68-year-old guitarist thought he was going to die when he was diagnosed with the life-threatening illness and wanted to quickly finish recording the final album '13' but thinks it upset the drummer, also 68.

Recalling receiving the news while recording their 2013 LP, he said: "My illness has changed my life a lot and my attitude. When I was going through my treatment, I didn't think I was going to last, I had stage three lymphoma.

"I wanted to get things going quick, and Bill wanted to take longer. Bill seemed to feel he was getting a bad deal. We never dealt with that, we left all that to management. We just wanted to play together and enjoy it. We were playing with Bill for a bit and then he never turned up. I thought, 'what's going on?"

The band are currently touring for the last time with 'The End' and Ward refused to take part, which Iommi regrets.

Speaking during an interview with MOJO magazine, he said: "'It would have been nicer to have Bill with us but unfortunately it never happened."

But Ozzy is determined the bandmates will speak again.

He told the publication: "At some point I wanna call him. I still love him, he's still my brother, but yuo have arguments. To be honest with you, I don't know what the f**k happened because I don't do the business side of it. I'm sorry Bill couldn't work something out, I really am. (But) I'm really glad we did this tour."