Energy work, both transactional and litigation, is a main driver behind strong 2012 financials at large Texas firms, although firm leaders also cite lateral hiring, a strong Texas economy, attention to collections and client year-end tax planning as major contributors.

The 25 highest-grossing firms in Texas brought in gross revenue totaling $5.4 billion in 2012, up from $5.3 billion in 2011. Some firms posted exceedingly good numbers for 2012.