Following Apple’s very public decision to break with its graphics core supplier Imagination Technologies, the UK firm says it has initiated a “dispute resolution procedure”, and has also put two of its three main business units up for sale. It aims to sell off processor core designer MIPs, and connectivity vendor Ensigma, to polish up its balance sheet in the wake of the Apple disaster. Imagination said last month that Apple – an investor and its largest customer – was going to try to develop its own graphics processing units (GPUs) for future iDevices, rather than using the PowerVR core and software. That led Imagination’s market capitalization to fall by over 60% to £290m. Apple accounts for about half of…