City sources predict the FTSE 100 will open 8 points lower from Monday's close of 6678 in a shortened pre-holiday session.London's stock market will close at 1230 local time and will remain closed for the following two days for the Christmas holiday.In an otherwise quiet day for company news, independent oil and gas exploration and production group Tullow Oil confirmed its exploration well on the Mantra prospect offshore Norway has encountered reservoir quality sands but all intervals are water wet. As a result, drilling at the well in the North Sea has been terminated and will now be logged before being plugged and abandoned.Elsewhere British Land and real estate investor GIC confirmed they have signed a joint venture agreement to develop Broadgate, a key office complex in London."This partnership provides us with the ideal platform to deliver the long-term vision for Broadgate. Our two organisations already know each other well and we look forward to working with GIC to deliver value for our respective shareholders from what is one of Central London's premier office locations," said British Land Chief Executive Officer Chris Grigg.BSkyB confirmed is has made a $350,000 equity investment in Jaunt, a technology company based in Palo Alto, California which specialises in video capture and display. "This investment will provide Sky with additional insight into developments within the field," BSkyB said.The Serious Fraud Office confirmed that it has launched a formal investigation into allegations of bribery and corruption at engine maker Rolls-Royce that could lead to criminal prosecutions.CJ