WRAPUP 2-U.S. judge rules for Asarco in $6-bln stock case

* Judge rules in favor of Asarco over Grupo Mexico unit

* Asarco had charged fraudulent transfer of stake

* Grupo Mexico shares slide 15 pct

(Adds Grupo Mexico comment, analyst comment; Changes dateline, pvs only NEW YORK)

NEW YORK/MEXICO CITY, April 2 (Reuters) - A federal judge in Texas has ordered a Grupo Mexico unit to return as much as $6 billion in stock and dividends to bankrupt U.S. copper miner Asarco LLC, sending shares in the Mexican parent company tumbling. U.S. District Court Judge Andrew Hanen, in the southern district of Texas in Brownsville, made his ruling on Wednesday in the fraudulent transfer case, according to court records.

"Justice has ultimately prevailed," Asarco's President and Chief Executive Officer Joseph Lapinsky said in a statement.

"This award is for the benefit of Asarco's creditors in the bankruptcy and should assist the company in its efforts to successfully emerge from Chapter 11 in the coming months."

Asarco brought the case against Americas Mining Corp, a subsidiary of Grupo Mexico (GMEXICOB.MX), accusing it of fraudulently transferring to itself Asarco's then 54.18 percent controlling interest in Southern Copper (PCU.N).