Pop star Jessica Simpson is expected to start the divorce battle with her husband of three years, Nick Lachey, in Los Angeles later today (16DEC05).

Simpson has instructed her attorney Robert Kaufman to file papers, citing "irreconcilable differences," according to American news magazine In Touch.

According to the publication, the decision to file papers came after the split couple spoke by phone on Wednesday (14DEC05) and were unable to resolve their personal problems.

A representative for Simpson would neither confirm nor deny the In Touch story.

The couple announced their split last month (23NOV05).