<p>The largest shareholder in Formula One (F1) motor racing has launched an attempt to buy a slice of the insurer of pension schemes at Cadbury, Siemens&nbsp;and ICI.</p> <p>Sky News has learnt that CVC Capital Partners has approached shareholders in Pension Insurance Corporation (PIC) to persuade them to sell their stakes in the business.</p> <p>The approach from CVC&nbsp;is said to value PIC - one of a crop of specialist pension buyout firms - at close to &pound;2bn.</p>