Halfords chairman Dennis Millard has increased his holding in the company on the same day the bicycle and car part retailer announced the acquisition of Nationwide Autocentres, a chain of car servicing and repair garages.He bought 15,000 shares at 431p a time, paying £43,100 and lifting his shareholding to 25,000 shares.Millard is relatively new to his current position, having joined the company in May. The shares have risen sharply since he bought his first tranche of shares in the firm, taking 10,000 at 310.2p a time soon after taking up the post.Aside from his post at Halfords he is a non executive director of department store Debenhams, electronic components distributor Premier Farnell and business services group Xchanging.His latest share purchase, which was announced today, was made on Friday, the same day Halfords announced the Nationwide purchase.Halfords is paying £73.2m in cash for Nationwide, which has 224 outlets across the UK.Nationwide will be rebranded as Halfords Autocentres. Halfords intends to boost the size of the chain by a further 200 centres over the next few years. David Wild, chief executive of Halfords, described the expansion into this market as a 'logical move' for Halfords, which already provides a fitting service at some of its stores. Top Director BuysHalfords Group (HFD) Director name: Mr Dennis H MillardAmount purchased: 10,000 @ 431.00p Value: £43,100London & St lawrence Inv Co. (LSLI) Director name: Mr Alan MaidmentAmount purchased: 8,150 @ 234.00p Value: £19,071Top Director SellsRockhopper Exploration (RKH) Director name: Mr Richard Faras VisickAmount sold: 3,855,296 @ 66.36p Value: £2,558,374Investec (INVP) Director name: Mr David MillerAmount sold: 18,750 @ 455.00p Value: £85,312BATM Advanced (BVC) Director name: Mr Koti GavishAmount sold: 111,370 @ 41.25p Value: £45,940