Massey has been struggling with losses after an explosion that killed 29 workers at a West Virginia coal mine last spring.
Alpha is paying $7.1 billion in cash and stock for Massey, the nation's fourth-largest coal producer by revenue. Massey operates 19 mining complexes in Virginia, West Virginia and Kentucky
including the Upper Big Branch mine where the April 5th disaster occurred.
Alpha is offering 1.025 share of its stock for each share of Massey, plus $10 per share in cash.
Together, that represents a bid of $69.33 per share, a 21 percent premium over Massey's closing
share price Friday.