Mexico industrial conglomerate Alfa said on Friday that it would become the sole shareholder of Alestra with the purchase of AT&T Inc's 49 percent stake for undisclosed terms.

The company said on Thursday that its first-quarter net profit more than doubled, driven by its petrochemical unit, which benefited from China's increased demand for polyester and nylon.

(Reporting by Patrick Rucker, editing by Gerald E. McCormick)