The Chief Executive Officer of chip designer Imagination Technologies has sold off a number of shares in the firm to pay income tax and national insurance of around £3.5m, due as a result of exercising nil-cost share options under the company's employee share plan. Following the £4.6m sale of 802,000 ordinary shares, Hossein Yassaie now holds 800,832 shares in the firm. At the beginning of January the firm took a stake in new company Toumaz Microsystems, a subsidiary of AIM-listed firm Toumaz. Imagination is set to invest £5m in the new company in return for a 25% stake. In mid-December the firm reported a 52% rise in adjusted pre-tax profit, which rose from £10.1m to £15.3m year-on-year for the six months ended October 31st. In the past 12 months Imagination's share price has soared almost 60%. In today's trading the stock gain 0.52% to 582.5p by 15:46.NRTop Director BuysWest African Minerals Corporation (DI) (WAFM) Director name: Mr Guy ElliottAmount purchased: 200,000 @ 16.50p Value: £33,000Immunodiagnostic Systems Holdings (IDH) Director name: Dr Patrik Olof DahlenAmount purchased: 10,782 @ 305.00p Value: £32,885Universe Group (UNG) Director name: Mr Stephen McLeodAmount purchased: 2,000,000 @ 1.50p Value: £30,000Top Director SellsImagination Technologies Group (IMG) Director name: Dr Hossein YassaieAmount sold: 802,000 @ 577.41p Value: £4,630,828