Thomas, who made the transaction via Potomac View Investments, sold the shares on Friday at an average price of 205p each, for a total value of £112.28m.
As of 1450 BST, Harbour Energy shares were down 0.19% at 212.60p.
Reporting by Iain Gilbert at Sharecast.com
Top Director Buys
Tatton Asset Management LSE:TAM
Director name: Mentel,Lothar
Amount purchased: 1,390 @ 732.90p
Value: £10,187.31
Top Director Sells
Harbour Energy NASDAQ:HBR
Director name: Thomas,Blair
Amount sold: 54,775,572 @ 205.00p
Value: £112,289,919.99