(Sharecast News) - Norwegian oil producer DNO has extended its 152p a share takeover offer for Faroe Petroleum by two weeks to 18 January.The company said on Thursday that it has received acceptances from 13.1% of Faroe shareholders. Taken together with its existing 29.9% stake in Faroe, this gives a level of 43%, which falls short of the 57.5% needed.DNO said it was extending the offer for a further 14 days despite the downturn in markets since its initial offer on 26 November."Faroe is a UK AIM-listed company and during this period, the UK AIM index has fallen by 9%, the Brent spot oil price has fallen by 11% and the average Brent futures oil prices for 2019 and 2020 have fallen by 11% and 9%, respectively," it noted."After careful consideration, including factoring in the likely challenge facing some shareholders to act during the Christmas and New Year holiday, DNO has decided to extend the offer."Executive Chairman Bijan Mossavar-Rahmani said: "Even if DNO's offer lapses or is allowed to lapse, DNO is not going away. For too long shareholders have given the Faroe board of directors a free pass. Starting with our first acquisition of shares, shareholders holding some 43% of Faroe's shares have voted with their feet by seeking to exit all or part of their positions either through sales to DNO or by accepting our offer."Whatever the outcome of this offer process, we will make every effort, through regular communication and engagement, to encourage our fellow shareholders who remain invested to vote their shares going forward not by proxy but proactively."Faroe has insisted on several occasions that the offer is opportunistic and significantly undervalues the group. On Wednesday, it said that its assets were worth up to $1bn according to an independent valuation by Gaffney, Cline & Associates, which implies a valuation in the range of 186p to 225p per share. This represents a 22%-48% premium to DNO's offer price.RBC Capital Markets said: "In our opinion, Faroe wants a higher exit price, rather than an independent future, and in the event that the deal lapses the board will have to deal with the demands of a major shareholder that 'will redouble efforts to replace entrenched directors and achieve appropriate board representation'."At 0955 GMT, Faroe shares were up 4.8% to 153.03p.