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June 11 (Reuters) - Dana DAN.N said on Thursday it would combine with Eaton's ETN.N mobility business in a deal valuing the unit at about $5.1 billion, as the auto supplier looks to benefit from strong demand for vehicle components.

Shares of Dana were up 5.5% and Eaton shares rose 3.3% in premarket trading.

The deal comes after Eaton said earlier this year it was planning to spin off its underperforming automotive businesses, which make technologies that manage and distribute power across vehicle propulsion systems.

The move will leave Eaton with a more focused portfolio centered on its electrical and aerospace businesses.