The deal is intended to help Network Rail carry out major improvements for passengers and reduce its reliance on taxpayers.
Following completion of the deal, Telereal and Blackstone will own equal interests and aim to be long-term owners of the estate.
The companies have announced what they call a ‘tenants first’ approach, which they claim will engage all property tenants and the wider community.
In addition, Telereal will look after the day-to-day property management activities of the portfolio.
Network Rail chair Peter Hendy said: “This has been a very thorough, detailed and complex process and we are pleased we’re now in a position to announce Telereal Trillium and Blackstone Property Partners as the new owners of the commercial estate.
“This deal is great news, for tenants it will mean significant commitment and investment, and for passengers and taxpayers it will mean massive, essential improvements without an extra burden on the public purse.”
In November last year, Network Rail launched the sale of its commercial estate portfolio, which comprises approximately 7,500 properties.
The sale includes 5,200 of the total properties and converted railway arches.
Network Rail has sold the sites on a leasehold basis with plans to retain access rights for using the property for railway operations in future.
Telereal co-founder and chairman Graham Edwards said: “The arches portfolio is a unique and vital part of the UK economy.
“We are tremendously excited by the prospect of working with its entrepreneurial tenant base, made up of car mechanics, bakeries, micro-breweries, restaurants, and just about every type of business you can think of. These tenants are a vibrant part of many local economies and communities.
“As a long-standing real estate investor in the UK, we and our partner Blackstone believe that our ownership of the portfolio will provide the supportive environment in which these businesses can flourish on a long-term basis.”
However, the proposed sale has raised concerns with existing tenants. Responding to the announcement, a Guardians of the Arches spokesperson said: “Throughout this process, we have sought to ensure that small businesses are genuinely protected so that the arches can thrive.
“We continue to dispute whether selling off the whole estate in one job lot is the best way of supporting small businesses and the local economies which rely on them.
“There is a long way to go in the sale process, but if Blackstone and Telereal successfully purchase the estate we trust they will follow up on their stated intention to put ‘tenants first’ in their management of the estate.
“A starting point would be to meet our demands for a full, transparent rent and lease audit, and to recognise Guardians of the Arches formally as a tenants’ association.”