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

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.

The Federal Trade Commission voted Tuesday to block mattress maker Tempur Sealy from buying retail chain Mattress Firm, a merger that regulators said would suppress competition and lead to higher prices.