The two companies initially announced their intention to merge on 6 March, and received regulatory approval on 25 July.
The investment business within the group is to be known as Aberdeen Standard Investments, and has assets under management of £583bn, and will have over 1,000 investment professionals based around the world.
The companies said 800 jobs would go as part of the merger
The company has clients in 80 countries, with offices in 50 countries and and a market cap of £11bn.
Keith Skeoch, chief executive of Standard Life Aberdeen, said today marked the culmination of many months of hard work and preparation, and the beginning of a new chapter.
"Our leadership team is in place and we have full business readiness from day one.
"Our people have worked exceptionally well together to complete the merger on schedule and we would like to thank them for this.
"The co-operation and collaboration we have witnessed bodes well for the on-going integration of the business, and in helping us create a world-class investment company for our clients, shareholders and our people.”
david.thorpe@ft.com
