Construction materials group SigmaRoc said it had agreed to acquire the remaining 60% of Welsh quarrying company GDH that it didn't already own for £7.5m.
The acquisition agreement followed the exercise of an exclusive option first announced in April 2019 and was expected to be completed on or around 21 September.
SigmaRoc had paid £4.9m for its initial 40% stake in had until the end of August 2020 to exercise the option.
The additional consideration would be funded through internal resources following 'strong' cash generation during the first half of 2020, the company said.
'The group's objective not to incur further dilution for equity holders for the acquisition of the remaining 60% shareholding was therefore achieved, making this transaction significantly earnings enhancing,' it added.