Josh Brolin and Diane Lane -- WE'RE DIVORCING

Another celebrity power couple bites the dust ... Josh Brolin and Diane Lane are calling it quits on their 8-year marriage.

A spokesperson for the couple announced the two are going their separate ways -- it's unclear if they have officially filed for divorce.

Josh and Diane were married in 2004 -- and have no children together.

The union hasn't exactly been smooth sailing -- just months after they tied the knot, Josh was arrested for spousal battery. The charges were later dropped.

Josh has starred in a ton of huge movies -- including "True Grit," "Milk," "No Country for Old Men" and "W."

Lane's credits ain't exactly shabby either ... she's been in hits like "The Perfect Storm," "Unfaithful," and "Under the Tuscan Sun."