Kim Kardashian's sister Khloe has called time on her troubled marriage to sportsman Lamar Odom by filing for divorce. The reality TV star, who has been estranged from the basketball player for months, filed documents to end the union and restore her maiden name on Friday (13Dec13). Khloe has cited irreconcilable differences for the split. The proceedings are expected to be very straightforward as both parties signed a pre-nuptial agreement. Kardashian will be represented by top divorce lawyer Laura Wasser. The couple wed in 2009 following a whirlwind romance, but things haven't been happy at home for years, according to reports suggesting Lamar's substance-abuse issues, which led to a DUI arrest in August (13) and a stint in rehab, put a strain on the marriage. There was a clear indication that Kardashian was planning to end the marriage at The Hollywood Reporter's Women in Entertainment Breakfast in Beverly Hills on Wednesday (11Dec13), when she arrived without her wedding ring.