Feb 5 (Reuters) - Steelmaker Acerinox has agreed to buy U.S. alloys manufacturer Haynes International for $798 million, Acerinox the Spanish company said on Monday.

If the deal is accepted by Haynes shareholders, they will receive $61 dollars per share in cash, corresponding to an enterprise value of $970 million, Acerinox said.

Haynes, which makes heat and corrosion-resistant alloys, currently trades on the Nasdaq Global Select Market. On completion of the deal it will become wholly owned by Acerinox's North American Stainless (NAS) business.

The transaction is expected to close in the third quarter of this year.

(Reporting by Joao Manuel Mauricio Editing by David Latona and David Goodman)