Taboola, the New York-listed online advertising company, has agreed to buy Dianomi, a smaller UK rival, in a cash deal worth up to £27 million.
Dianomi shareholders will receive 64p in cash for each share, valuing the business at around £19 million.
They may also get up to a further 24p a share through a contingent payment, lifting the total to as much as 88p and the headline value to £27 million.
The cash element alone represents a 68% premium to Dianomi's closing price of 38p on Wednesday, the last trading day before the announcement.
Against the six-month average share price of 14.2p, the premium rises to 350%.
Dianomi, which listed on London's junior AIM market in 2021, places advertising for finance and business clients such as Charles Schwab and Bank of America across premium publishers including Reuters and the Wall Street Journal.
The company has struggled as a small quoted business, citing thin trading in its shares and a persistent gap between its share price and what its board considers the underlying worth of the business.
It also pointed to a fast-changing advertising market, where the rise of artificial intelligence and "zero-click" search is altering how readers find content, demanding fresh investment in technology.
Taboola, whose advertising platform reaches more than 600 million daily users through publishers such as Yahoo and NBC News, said the deal would add a specialist finance-focused network to its business.
The extra 24p a share depends on some of Dianomi's publishers adopting Taboola's standard contract terms, so may not be paid at all.
Shareholders holding 75.3% of Dianomi have already agreed to back the takeover.
The deal is structured as a court-sanctioned scheme of arrangement and is subject to clearance from the Competition and Markets Authority.
It is expected to complete before the end of 2026, after which Dianomi will delist from AIM.
