Jan du Plessis, the new chairman designate of drinks giant SABMiller, has celebrated his first day on the job with the purchase of 30,000 shares. Du Plessis, who left Marks & Spencer to take up the new role at the Peroni brewer, paid 3,312.50p apiece. He will replace John Manser, who has delayed his retirement by one year, to July of 2015. Du Plessis is now a non-executive director of SABMiller and will step down from the board of M&S in the first half of next year. SBG Securities has reiterated its 'hold' rating on the group.Top Director BuysSABMiller (SAB) Director name: Mr Jan du PlessisAmount purchased: 30,000 @ 3,312.50p Value: £993,750Nostrum Oil & Gas (NOG) Director name: Mr Piet EveraertAmount purchased: 3,000 @ 755.22p Value: £22,657NR