The Australian investment bank has appointed advisers at PJT Partners to carry out a strategic review of KCOM.
The review could result in a sale of the telecoms firm or a merger with a rival network provider.
But it is understood that no decision has been made on the company's future yet.
Macquarie bought KCOM for £627 million in 2019 after seeing off a rival bid from pension fund Universities Superannuation Scheme.
Under Macquarie's ownership, the number of homes now passed by KCOM’s full fibre deployment has risen to around 300,000, up from 200,000 in 2020.
KCOM, which was founded in 1904 as Kingston Communications, has long held the monopoly in the Yorkshire city.
The company was previously listed on the London Stock Exchange and was once had a market value of almost £5 billion.
But its dominance has been challenged by the arrival of altnet providers. Cityfibre, Connexin, Grain and MS3 Networks have all begun to build rival networks in Hull in recent years.
KCOM has also begun opening up its network to more third-party internet service providers.
KCOM turned its first pre-tax profit under Macquarie’s ownership in the year to the end of March 2023.
Virgin Media O2 and Cityfibre are among potential suitors should the company be put up for sale.
Macquarie declined to comment.
KCOM didn’t immediately respond to a request for comment.