LONDON, Feb 4 (Reuters) - Britain’s Rolls-Royce said it agreed to sell its Bergen Engines unit to Russia-based TMH Group for 150 million euros ($180 million), making initial progress with a disposal plan aimed at helping it survive the pandemic. The aero engines-maker is aiming to raise 2 billion pounds in total from asset sales, and the disposal of Norwegian-based Bergen announced on Thursday follows that of another small business, its civil nuclear instrumentation unit, last December.