Robin Wright Penn files for divorce

<p>Sean Penn may soon be a single man walking. Robin Wright Penn has filed for divorce from the actor and director, according to media reports.</p><p>Papers were filed Dec. 21 in Marin County Superior Court. Wright Penn cited irreconcilable differences as a reason for the split, which was first reported by the Web site CelebTV.com.</p><p>The couple has two teenage children and are seeking joint custody.</p><p>Penn directed "Into The Wild" and starred as a death row inmate in "Dead Man Walking."</p><p>Wright Penn's acting credits include "Beowulf" and "Breaking and Entering."</p>