Gulf Energy Development Pcl, Thailand’s biggest power producer by market value, offered to acquire Intouch Holdings Pcl that control’s the nation’s largest mobile phone operator for as much as 169 billion baht ($5.4 billion). Intouch shares surged the most in more than a year.

The Bangkok-based company, controlled by billionaire Sarath Ratanavadi, offered to buy 2.6 billion shares, or about 81% of Intouch, that it doesn’t already own at 65 baht each, it said in an exchange filing. The offer price is 11% higher than Intouch’s close on Friday. While Intouch shares jumped as much as 9% on Monday, the most since March 2020, Gulf Energy tumbled as much as 5.3% to its lowest level since November.