UK stocks are expected to open broadly flat on Monday morning as the 'fiscal cliff' in the US continues to dominate market sentiment ahead of the Christmas holiday.City sources are expecting the FTSE 100 to open just four points higher than Friday's close of 5,922.Market analyst Craig Erlam from Alpari said this morning: "Negotiations will continue this week between Barack Obama and John Boehner, with investors hoping for an acceptable compromise. Both are retaining a tough stance in the media, showing no signs of budging on the main issues including spending cuts on entitlements, tax hikes on the top 2% of earners and raising the debt ceiling."This tough stance is paralysing the markets as investors become less and less convinced that a deal with be done. It seemed unthinkable a few weeks ago that the country would be allowed to go over the cliff but unless both parties soften their stance a little and actually negotiate, that is exactly what we'll see, with the stock markets falling off a cliff of their own."Company newsTemporary power and temperature control solutions group Aggreko maintained its full-year guidance in a pre-close trading update this morning, but gave a gloomy outlook for next year, saying that its performance would likely be lower than the 2012.The company said that group revenues are expected to rise by 13% in 2012 to £1.6bn, while profit before tax and amortisation will be up 12% at £365m.Egypt-focused gold mining and exporting company Centamin has confirmed that the halt by customs on gold exports from Sukari has been lifted and a shipment was made on Sunday December 16th. A statement published by the company said: "We expect both fuel supply and normal operations at Sukari to resume in the coming days, once payment for the latest shipment has been received and working capital in the operating company, Sukari Gold Mines, has subsequently been replenished. Centamin will provide a further market update when this occurs."In small cap news, Kazakhstan gold mining and development company, Hambledon Mining, has appointed Aidar Assaubayev as its new Chief Executive Officer. Assaubayev will focus on a comprehensive review of the AIM-listed company's operations and strategic options with a view to identifying the best way forward for Hambledon and its shareholders. BC