Federal regulators say Tempur Sealy's acquisition of Mattress Firm would raise prices for "millions of consumers."

Deal documents show the company wants to “kneecap competitors and dominate the market,” one Federal Trade Commission official said.

The Federal Trade Commission has unanimously voted to bring a lawsuit against mattress maker Tempur Sealy to block its $4 billion acquisition of Mattress Firm, saying the deal would allow the world's largest mattress supplier to suppress competition that would result in higher prices for shoppers.