Arris Group said Wednesday it will buy British set-top box maker Pace for $2.1 billion in cash and stock and reincorporate in the U.K. to cut its taxes.

Shares of Arris surged $7.46, or 24.4 percent, to $38 in after-hours trading.

Arris posted $5.32 billion in revenue in 2014 and said the two companies will have about $8 billion in annual revenue combined. The boards of both companies have approved the sale, and they expect to complete the deal in late 2015 pending regulatory clearance.

The new company will be incorporated in the U.K. and will have its headquarters in Suwanee, Georgia, where Arris is now based. It will keep Arris' "ARRS" Nasdaq ticker.

Arris Group Inc. makes high-speed Internet equipment, and in 2013 it paid Google Inc. more than $2 billion to acquire for set-top operations that once belonged to Motorola Mobility.

Google bought Motorola Mobility in 2012 for $12.4 billion but didn't hold on to most of the acquired business for very long. It sold its set-top operations to Arris Group Inc. for $2.35 billion and its smartphone assets, along with some 2,000 patents, to Lenovo.