(CNN) -- Two of the largest US regional banks are joining forces in a bid to compete with the nation's biggest players.

BB&T and SunTrust on Thursday announced a $66 billion merger, forming the sixth-largest US bank based on assets and deposits.

"It's an extraordinarily attractive financial proposition that provides the scale needed to compete and win in the rapidly evolving world of financial services," BB&T CEO Kelly King said in a statement.

The combined company will operate under a new name, though the banks have not yet decided what it will be called. Its headquarters will be in Charlotte, North Carolina, but the bank will also have significant operations in Winston-Salem, North Carolina, and Atlanta.

Together, BB&T and SunTrust will have about $442 billion in assets, $301 billion in loans, and $324 billion in deposits, the companies said.