Aga Foodservice Group said it was "bringing the family back together" after it bought the Irish stove manufacturer Waterford Stanley for £9.3 million.
The two companies were once linked, but went their separate ways in the 1950s.
Aga, which manufactures Rayburn cookers, bought the Irish-based business from the US financial services group Pricoa.
The Solihull-based firm said it was going to pay £4.65 million for the equity and assume the £4.65 million of debt accumulated by Waterford Stanley.
Waterford Stanley specialises in the cast iron cooker market through its Stanley ranges which are comparable to Aga's Rayburn cookers.
It sells around 5,500 cookers a year, while it also manufactures and distributes 9,000 stoves annually. In recent years it has restructured its operations, closing much of its manufacturing capacity and international operations.
The costs have held back its financial performance, and although it made an operating profit of £911,000 in the year to March 31, after the reorganisation was accounted for, it made a loss of £945,000.
Waterford Stanley employs 170 people of which 80 are in manufacturing.
William McGrath, chief executive of Aga said: "We are the market leader in heat storage cookers and have developed that position over a number of years in the UK.
"In Ireland Stanley is the market leader. We had long thought it would be a good opportunity to bring the family back together again.
"Stanley was created at the same time as Rayburn in Scotland in the 1920s, and till the 1950s they were together."
Mr McGrath said Aga would look to start rolling out Stanley's display centre concept at its dealerships across the UK.
He said that some of the manufacturing work for Stanley products could be undertaken in the Midlands, while the firm targeted further growth in Ireland.