The announcement comes one day after Mike Ashley’s sportswear firm dropped a breach-of-confidentiality claim against Rangers, which a High Court judge had branded “ridiculous”.
King was earlier cleared of contempt of court following an allegation by the Newcastle owner, whose legal fight has now been taken to the Scottish Football Association in a Court of Session dispute over his punishment for breaching rules over dual influence.
It previously emerged that Rangers were locked into a seven-year contract with Sports Direct, so a long legal battle looks set to continue.
The club board recently raised £5 million through shareholders to pay off a loan from Sports Direct, whose owner Ashley holds a nine per cent stake in Rangers and had several allies on the board before King and others swept to power 11 months ago.
After outlining recent investments in the playing squad, training ground and stadium, King said in a statement: “A further unanticipated investment was made to pay off the Sports Direct loan and to recover all security held by Sports Direct.
“That has now been completed and the club has formally given notice to end the relationship with Sports Direct while still reserving our right to proceed with challenges to the existing suite of contracts and side agreements in a court of law.”
Sports Direct were ordered to pay legal costs estimated at £400,000 following its failed action at the High Court in London.
King said: “For the first time a board of this club has stood up to the threats of Sports Direct and has achieved resounding success in court proceedings including the substantial recovery of legal costs.
“Sports Direct’s motives were severely exposed when a High Court judge ruled that Sports Direct abused court processes in its attempt to bully the club and me.
“We will continue to put Rangers first and ensure that we get redress and compensation for the poor commercial and business practices that the club has been forced to endure.”
In a general update to supporters, King added: “Overall, the club is in a substantially better position - on and off the pitch - than it has been for some time.
“The board continues to ensure that the club is run within the balance required to secure success on the pitch while simultaneously funding the cash shortfall that is required until we have a sustainable business model.
“The club has not secured fair value for much of its expenditure over the last few years. Under the present board that is no longer the case.”
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