Dundee technology firm i-design, an innovator in cash machine marketing, is being taken over by Cardtronics.
The agreed deal with the UK subsidiary of the US operator of Automated Teller Machines (ATM) values the Scottish firm at £8.5m.
That is a premium of 161% over the Tuesday closing price of the company, listed on the Alternative Investment Market.
It is 51% higher than the average over the past 12 months.
James Faulds, chairman of i-design, said: "The Offer will allow i-design Shareholders to realise a significant cash premium for their shares and provide i-design with the opportunity to accelerate its growth and widen its reach in a way not currently available. We believe the Offer is a good outcome for all i-design stakeholders."
The announcement came with agreement to the proposed takeover from owners of more than 60% of shares. It lifted the share price on Wednesday from 23p to 59p.
Steve Rathgaber, chief executive of Cardtronics, said: "At Cardtronics, we gravitate to opportunities and environments where the company can draw multiple sources of revenue from a single ATM by providing additional services."
He said his company's access to funding and its relationship with retailers could expand i-design's market.
Mr Faulds, who founded Faulds Advertising in Edinburgh, has a 4% stake in i-design, which means a £379,000 pay-out.
Chief executive Ana Stewart, a co-founder of the firm, has a shareholding worth £1.36m.
Founded in 1991 and entering the ATM market in 2004, the Dundee company has developed advertising and marketing software that has been installed on 30,000 ATMs in deals with several banks in Canada and Britain. It also sells advertising space.
In its most recent annual accounts for the year to 30 September, i-design reported revenue of £3.3m, down from £3.5m the previous year.
Profit before tax was £217,000, more than double the equivalent prior-year end period in 2011, as it moved towards software sales.
Cardtronics operates ATMs and financial services kiosks for client banks and for retailers.
It operates in the US, as well as Canada and Mexico.
Cardtronics UK was a subsidiary set up to buy i-design.