Spain’s Repsol SA will acquire one of the largest remaining independent oil and gas firms in Calgary in a $12.9 billion all-cash deal, both companies said Tuesday.

The deal by Repsol to acquire Talisman Energy Inc. should vault the Spanish company into the top 15 largest privately owned oil and gas companies globally, Repsol said. It’s also the largest acquisition of a Calgary independent oil and gas firm since Chinese state-owned petroleum giant CNOOC bought Nexen Inc. in February 2013. The latter was named “Global M&A Deal of the Year” for Canada by The American Lawyer that September.