Standard Life's chairman has warned that a Brexit would be "potentially damaging to the UK economy", saying his company backs the UK remaining a member of the European Union.
In the chairman's statement, as the business revealed a strong set of results, Sir Gerry Grimstone said the business was "conducting a thorough study of the impact of this on our business".
Grimstone said: "The debate on whether or not the United Kingdom should stay part of the European Union (EU) is reaching its climax and coming closer to the time when the UK public will have their say... We believe that access to the EU single market is in the best interests of our customers and clients.
"The principle behind the single market - to encourage the free movement of goods and services - has created an environment that gives individuals and businesses the confidence to invest for the long term and it would be potentially damaging to the UK economy and therefore to companies such as Standard Life if the UK were to leave it."
He noted it was "unusual" for Standard Life to get involved in political issues, but did on issues like this, which were "central to our continued success".