The data showed men on average earned 47.2 per cent more than women at St James's Place last year.
Women at the firm also received 80 per cent less in bonuses than men on average.
The company said the gap was due to a lower proportion of women in senior roles.
“In simple terms, we know that we need to increase the number of women in senior roles to reduce our pay gap,” said chief executive Andrew Croft.
“St. James’s Place is committed to evolving a culture in which everyone can thrive and the broad range of initiatives we are implementing is focused on bringing down the gap.”
New initiatives include adapting its recruitment approach to ensure that at least a third of external candidates shortlisted for senior positions are women, as well as establishing a Diversity and Inclusion Committee.
“We’ve also made gender pay a key objective for 2018,” Mr Croft said. The company has established a Diversity and Inclusion Committee and said it had made gender pay a key objective for 2018.
The company said it had enhanced its maternity provision with improved support for returning employees and an aim of achieving a 90 per cent ‘return’ rate.
All UK companies with more than 250 employees are required to publish details of the difference in pay between men and women by 4 April.
Employers are required to publish the difference between the average hourly rate of pay paid to male and female employees, between the average bonus paid to male and female employees, the proportions of male and of female employees who receive bonuses, and the relative proportions of male and female employees in each quartile pay band of the workforce.
The move is part of attempts to fight workplace discrimination.
Currently men across all industries are average paid 18.1 per cent more than women. For just full time staff this is 9.4 per cent for full-time.
Prime minister Theresa May said in October 2017 "tackling injustices like the gender pay gap is part of building a country that works for everyone".
"Already many of the UK’s top companies are leading the way in making sure everyone’s contributions to the workplace are valued equally, and it is encouraging news that the gap has fallen this year for full-time workers.
"But the gender pay gap isn’t going to close on its own – we all need to be taking sustained action to make sure we address this.
"We need to see a real step-change in the number of companies publishing their gender pay data and offering progression and flexibility for all employees.
"That’s why today I am calling on more businesses, both small and large, to take action to make sure the gender pay gap is eliminated once and for all."
However financial adviser Julie Lord, chief executive of Magenta Financial Planning in Bridgend, and former president of the Institute of Financial Planning, said that although targeting the gender pay gap is important, it is also about making the workplace flexible for female workers.
“I think in many cases we could earn more, as we’re empathetic and have real rapport with clients, but often people have other goals in mind. For example, I only work three days a week,” she said.
