LONDON — British Treasury chief Rachel Reeves is to announce plans later Thursday to merge dozens of pension funds, with the aim of unlocking tens of billions of pounds for investment and boosting Britain’s sluggish economic growth.

In comments released by the Treasury ahead of his speech to financial leaders in central London, Reeves will say the creation of so-called “mega-funds” will represent “the biggest pension reform in decades”.

In his first so-called Mansion House speech, an annual ritual for British Chancellors of the Exchequer, Reeves will say the changes could help unlock 80 billion pounds ($100 billion) of investment. Pension funds invest in a variety of assets such as stocks, bonds, real estate and infrastructure in an attempt to increase retirement benefits for their members.

The proposed merger of 86 local authority pension funds in England and Wales echoes schemes undertaken in Australia and Canada, where pension funds are believed to have taken advantage of their larger size to invest in assets and boost growth . By 2030, the new local government pension scheme in England and Wales is set to manage around £500 billion in assets by 2030.

The new Labor government will introduce the reforms through a new bill in parliament next year. Early signs suggest it has broad support across the political divide – the former Tory government had indicated it would go down that path as well – and within the pensions industry.

“Larger pension schemes can help deliver better outcomes for savings through economies of scale, stronger governance, bargaining power and additional resources,” said Zoe Alexander, director of policy and advocacy at the Pensions and Savings Association on life, an organization that seeks to bring the industry together and promote best practice.

Business leaders cautiously welcomed the reform plan but said the government must work hard to win their support following Reeves’ tax hike budget last month.

“As the Budget heaps extra costs on businesses and squeezes their investment space, the Government must work hard to restore confidence in the UK as a place where businesses and communities can succeed,” said the Confederation’s chief economist British Industry, Louise Hellem.

“Pension schemes will want to operate in a thriving UK economy,” she added.

Since the global financial crisis of 2008-2009, the UK economy has underperformed compared to previous years. The main purpose of government is to support economic growth. Friday’s figures are expected to show the economy barely grew in the second quarter of the year.