ResMed (RMD) said Tuesday it entered into a $450 million accelerated share repurchase agreement with Citigroup's (C) Citibank, funded with proceeds from the sale of its MatrixCare business and cash on hand.

ResMed will pay Citibank $450 million on Thursday and expects an initial share delivery that day equal to 80% of that amount based on the Wednesday closing price. Final settlement is scheduled for December, according to a regulatory filing.

The buyback is being conducted under a repurchase authorization for 20 million shares approved by the board in February 2014.