Johnston Press has confirmed it has reached a deal to buy the i newspaper from ESI Media for £24m.
Johnston, which owns The Scotsman and more than 200 other titles, said the purchase was subject to shareholder approval.
It will pay £22m in cash once the deal is completed and the rest on 20 April.
The announcement came as ESI confirmed that the i's sister titles, The Independent and Independent on Sunday, will halt print editions in March.
In a statement, Johnston said the i acquisition would create the UK's fourth-largest print publisher with more than 600,000 paid copies a day.
The i became Britain's first new daily national newspaper in nearly 25 years when it launched in 2010 with a cover price of 20p. According to the Audit Bureau of Circulation (ABC), the newspaper sold nearly 270,000 copies daily in December.
Johnston said its directors believed the i provided a "strong strategic fit" and would help build the group's national print and digital display advertising revenues.
The move is also expected to strengthen its existing portfolio, which includes The Scotsman, The Yorkshire Post and the Belfast-based Newsletter.
Johnston chief executive Ashley Highfield said: "This is a transformational acquisition for Johnston Press and an important step towards delivering our long-term strategy.
"i is a highly-regarded newspaper with a clear market position and a loyal readership.
"By joining with Johnston Press the combined circulation will be equal to 9% of national daily circulation, making us the fourth-largest player in the market.
"This enhanced reach represents a significant growth opportunity for Johnston Press in terms of national print and digital advertising revenue. It also rebalances our revenues towards less volatile circulation revenues.
"With our considerable digital experience the combination of Johnston Press and i will also allow us to grow digital audiences and revenues through the creation of inews.co.uk."
Johnston Press recently revealed plans to cut editorial jobs across its operations in the UK as part of a bid to reduce costs following a decline in revenue.
Shares in the publisher rose earlier this month after it said it expected a major reduction in its pension scheme deficit.