MELBOURNE, Aug 29 (Reuters) - Lynas Rare Earths is actively seeking partners to build out a downstream business in the United States, CEO Amanda Lacaze said on Tuesday.

The Australia headquartered firm that is the biggest producer of rare earths outside of China is building a plant to process heavy rare earths in Texas.

"We are actively engaged in that process as we speak," Lacaze told an earnings call. (Reporting by Melanie Burton; Editing by Muralikumar Anantharaman)