March 15 (Reuters) - Texas lawmakers on Monday were preparing legislation to cut about $5.1 billion in disputed electricity and services fees levied during a winter freeze that sent the state’s power market into financial crisis. Governor Greg Abbott submitted an emergency proposal authorizing legislators to address billing errors and service fees that led to a heated battle between lawmakers and the state’s power regulator over who can rescind the charges. (Reporting by Gary McWilliams Editing by Nick Zieminski)