(Updates)

** Shares of U.S.-based electric utility Constellation Energy soar nearly 25% to an all-time high of $304.68

** Company to buy independent power producer Calpine Corp in cash-and-stock deal valued at $26.6 bln including debt

** CEG and Calpine to have nearly 60 gigawatts of capacity from zero- and low-emission sources, including nuclear, natgas, geothermal, hydro, wind, solar, cogeneration and battery storage

** "Calpine's low-emission natural gas plants will play a key role in maintaining grid reliability for decades to come as customers transition to cleaner energy sources" - Constellation

** CEG adds transaction is projected to add more than $2 bln of free cash flow annually

** Deal is expected to close within 12 months of signing

** "The combination makes CEG bigger in Texas and reduces exposure to PJM. The supply-demand situation in those regions appears very favorable" - Tim Winter, portfolio manager at Gabelli Funds

** Stock was up 93% in 2024

(Reporting by Pooja Menon in Bengaluru)

((Pooja.Menon@thomsonreuters.com;))