Royal Dutch Shell is expecting its fourth quarter profits to drop by at least 40% year-on-year, falling to between $1.6bn and $1.9bn following the collapse of crude oil prices.

Ben van Beurden, chief executive of the Anglo-Dutch oil company has told shareholders that he is "pleased with Shell’s operating performance in 2015, and the momentum in the company to reduce costs and to improve competitiveness."

Shell is currently in the process of acquiring BG in a deal worth £36bn.

Mr van Beurden said that, "The completion of the BG transaction, which we are expecting in a matter of weeks, will mark the start of a new chapter in Shell, to rejuvenate the company, and improve shareholder returns."

"Synergies from the BG combination will be in addition to that. Together, these actions will include a reduction of some 10,000 staff and direct contractor positions in 2015-16 across both companies, as streamlining and integration of the two companies continue," Shell said in a statement which will make for uneasy reading for employees of both companies. 

The firms operating costs fell by $4bn (close to 10%) in 2015 - costs are expected to fall by a further $3bn during 2016.

*Update 22/1 - A previous version of this story incorrectly referred to BP rather than BG in the third paragraph