Xstrata has sought more time to complete its $80bn merger with commodities trader Glencore, as it seeks to address shareholder concerns about the governance and strategy of the combined company. It is yet another twist in seven-month battle to seal a tie-up that is one of the biggest the resources sector has seen in years. In a statement on Friday, the London-listed miner said it had requested the extension from the UK Takeover Panel until October 1, to "enable Xstrata's independent non-executive directors to take full account of feedback from consultation with key Xstrata shareholders." People close to the talks said some shareholders remained implacably opposed to generous retention payments designed to keep Xstrata's senior managers in place after the deal's close. However, they added, the move by Ivan Glasenberg, Glencore's chief executive, to install himself as the boss of the combined company had raised concerns among other investors that Xstrata could face an exodus of key staff. While the retention packages for Xstrata's senior staff remains an outstanding issue, the delay was also needed to address how Mr Davis's departure would be handled and the composition of the combined company's board. One of the people said that some shareholders needed assurances that there would not be a change in Xstrata's strategy, whose assets will be contributing a large portion of the new company's earnings. Earlier this month, Mr Glasenberg made a last-ditch attempt to save the merger after opposition from top Xstrata shareholders, increasing the offer from 2.8 shares to 3.05 shares but asking that he become chief executive of the combined group in six months. Xstrata's board is expected to keep the substance of the retention arrangements set out in May, adjusting only for Mr Davis's departure. Payments would be made to about 70 of the miner's senior staff totalling about £140m, people familiar with matter said. The performance hurdles would be similar to those introduced earlier this year, after shareholder outcry forced Xstrata's board to tweak its proposals. Under the new proposals, Mick Davis's previously promised £29m package would no longer form part of the scheme, nor would other executives" payments accelerate on his departure, as had been intended. The Qatar sovereign wealth fund that is Xstrata's largest independent shareholder is still undecided about whether to support the deal, a person close to talks said. The delay follows final-hour board meetings on Thursday afternoon to see if the miner could recommend a deal on Friday.