Shares of TXNM Energy (TXNM) traded at an all-time high Monday when the power provider for New Mexico and Texas agreed to be purchased by the infrastructure unit of Blackstone (BX) for $11.5 billion in cash and debt.

The deal has Blackstone Infrastructure paying TXNM investors $61.25 for each share they own, a nearly 16% premium to the closing price on Friday. To support TXNM's growth, Blackstone Infrastructure will spend $400 million to acquire 8 million newly issued shares of TXNM common stock at $50 each through a private placement agreement, and TXNM is to match that amount before the close of the transaction, which is expected in the second half of 2026. 

Sean Klimczak, Global Head of Blackstone Infrastructure, said the company invests long-term, and "we look forward to having the opportunity to engage in meaningful dialogue about how we can create win-win, growth-oriented investments across both states."

As part of the acquisition, TXNM Executive Chair Pat Collawn will step down, and current Chair and CEO Don Tarry will oversee operations as President and CEO.

TXNM Energy shares surged 7% to $56.60 about an hour after the opening bell Monday after earlier hitting a record $57.29. Blackstone shares slipped 1%.