The company reported it had made £141m profit compared to £165m in the same period last year.
The IFP corporate member said this “reflects on-going momentum in fee business offset by an expected £37m reduction in spread/risk margin due to lower annuity sales and reduced benefit from asset liability management”.
Assets under administration went up to £302.1bn from £296.6bn at the end of last year and rose from £223.9bn in the first half of 2014.
The company also reported that third party net inflows stood at £5.2bn despite outflow from low revenue margin mandate of £1.7bn.
It added 120,000 new customers in the UK through auto-enrolment in the first half of this year, contributing to a 15% increase in regular contributions into workplace pensions.
The firm also increased wrap assets by 11% to £23.3bn, with the net inflows up 17% to £2.1bn.
Chief executive David Nish will leave the job in August after six years in charge and Keith Skeoch, currently chief executive of Standard Life Investments, will succeed him. His exit was announced in June.
Mr Nish said as part of today’s results report: "It has been an absolute privilege to lead Standard Life for the last six years and to help build our business into the strong global player it is today.
“I wish Keith and the inspirational people across all of our group every success for the future. Standard Life is very well positioned to deliver on-going growth and to help our customers and clients to save and invest, so that they can look forward to their financial futures with confidence."
He said: "Standard Life has performed well during the first half of 2015 driven by a focus on providing value for our customers, clients and shareholders.
“We are continuing to see the benefits of our expanding distribution capabilities and strategic relationships with 70%4 of net inflows from outside the UK and strong growth in net inflows through the wholesale channel.”