David Sullivan
Businessmen Gold and Sullivan pose after announcing their take over of West Ham United at Upton Park football ground in east London. REUTERS

West Ham co-owner David Sullivan has cautioned Newcastle they face losing striker Demba Ba in a cut-price deal, unless they can agree terms on a new contract.

Ba has been a revelation since joining from West Ham last summer. The striker has scored 16 goals in 21 appearances as the Magpies challenge for a Europa League place.

Nevertheless, Sullivan has warned Newcastle that Ba could leave for a reduced fee if they do not resolve the issue of his much-publicised release clause.

In January, Tottenham manager Harry Redknapp revealed Ba could be sold for as little as £5m, due to a section in his contract that would force Newcastle to sell should they received such an offer. Ans Sullivan backed up these claims, saying that the Toon's deinals of such a clause are not accurate.

"I'm told he's got a £7 million get-out at Newcastle and he gets half the money over that," Sullivan told the Web site West Ham Till I Die. "They keep denying it, but I think you'll see in the summer he will leave Newcastle, or he'll get a monstrous rise to stay there.

"If they get about £4 million, half will go to him, so if they sell him for £7 million, they'll only net about three because they paid his agent £2 million to get him out of here. Getting £3 million is not bad, but for a player of his quality, it's not fantastic."

And Sullivan knows all too well how painful it can be after he lost Senegal international Ba to Newcastle for nothing in the summer.

Ba moved to Upton Park from German side Hoffenheim on a three-and-a-half year contract in January 2011.

The club agreed a clause under which his wages would be halved if they were relegated, and he could leave if they suffered that fate.

"It's one of those mistakes that happen, but it's probably one of the worst mistakes I have ever made in my life," Sullivan added. "It just didn't enter our heads. It didn't enter anybody's head that he'd score enough goals that we'd want to give him £40k a week and his old club £15-20k an appearance and we'd still be relegated.

"In reality, that's exactly what happened. The agent just threw it in at the last minute. He said, 'Obviously if his salary is cut by 50%, you've got to let him walk'. We thought, 'Okay, if we get relegated, do we really want a £40k-a-week striker in the Championship?'.

"Well, we would have because he was devastating. If he was with us now and his knee had held up - because remember, he did have a very, very bad knee - I think we'd be 15 points clear, I really do. He'd be cutting through those defences. You live and you learn."