Colt chief executive Rakesh Bhasin took advantage of a sharp drop in the communications company's share price to buy a big stake.The firm, which used to be called City of London Communications, yesterday announced a revenue decline of 3.5% in the first half of the year, mainly driven by a decline in mobile termination rates. "While economic conditions remain challenging, we continue to see signs of improved pipeline," Bhasin said. "We expect incremental growth in the latter part of the year."The shares dived following the announcement, allowing Bhasin to pick up 200,000 at 119.5p a pop. He paid a total of £239,000.He now has 800,000 shares.Top Director BuysCOLT Group SA (COLT) Director name: Mr Rakesh BhasinAmount purchased: 200,000 @ 119.51p Value: £239,020Rolls-Royce Group (RR.) Director name: Mr James M GuyetteAmount purchased: 5,703 @ 654.29p Value: £37,314Amphion Innovations (AMP) Director name: Mr Richard James MacaleerAmount purchased: 577,107 @ 2.40p Value: £13,851Amphion Innovations (AMP) Director name: Mr Richard James MacaleerAmount purchased: 577,107 @ 2.40p Value: £13,851Sacoil Holdings (DI) (SAC) Director name: Mr Colin BirdAmount purchased: 200,000 @ 6.25p Value: £12,500