The financial director of BT Group sold £1.8m worth of shares on Friday.Tony Chanmugam sold 400,000 shares in the British multinational telecommunications group at an individual price of 442p, pocketing a total of £1.768m in the transaction.Chanmugam, who joined the company in 2008, now holds 574,882 shares.Also on Friday, Frances Chanmugam, a connected person, sold 9,000 shares for 445p each, bringing home £40,050 after the sale.The sale follows news that BT rivals claimed the market incumbent needs to be further broken up to improve the market for consumers.However, BT spokesperson, Dan Thomas, said "the sale had been agreed prior to the review coming out." "Given the various other large announcements taking place in January and February, Tony has not been in a position to sell those shares, which he wanted to use for charitable work."The "overarching review" will scrutinise competition, investment, innovation and the availability of products in the broadband, mobile and landline markets.Broker Killik said: "While this review will take some time to complete, there is a possibility that it could be negative for BT and we will be following it closely."TalkTalk noted that BT's retail division currently has a market share of around 40%, while in wholesale this rises to nearer 70%.However, Berenberg analysts said the £12.5bn acquisition of EE last month will make BT "the largest mobile player in the UK".Top Director BuysTungsten Corporation (TUNG) Director name: Mr Edmund TruellAmount purchased: 390,000 @ 186.00p Value: £725,400Independent Inv Trust (IIT) Director name: Mr Maxwell C B WardAmount purchased: 50,000 @ 298.38p Value: £149,190Flybe Group (FLYB) Director name: Mr David J KapplerAmount purchased: 100,000 @ 58.00p Value: £58,000Alkane Energy (ALK) Director name: Mr Neil Christopher O'BrienAmount purchased: 50,000 @ 20.50p Value: £10,250Top Director SellsBT Group (BT.A) Director name: Mr Tony ChanmugamAmount sold: 400,000 @ 442.00p Value: £1,768,000Galliford Try (GFRD) Director name: Mr Ken GillespieAmount sold: 93,396 @ 1,503.91p Value: £1,404,592Keller Group (KLR) Director name: Mr Justin R AtkinsonAmount sold: 48,269 @ 962.49p Value: £464,584Keller Group (KLR) Director name: Mr James HindAmount sold: 34,733 @ 962.49p Value: £334,302Keller Group (KLR) Director name: Mr Wolfgang SondermannAmount sold: 32,907 @ 962.49p Value: £316,727BT Group (BT.A) Director name: Mr Tony ChanmugamAmount sold: 9,000 @ 445.00p Value: £40,050