Higher revenues, especially from commercial clients, helped Ecology & Environment increase its fourth-quarter profits by 13 percent, the Lancaster-based environmental services firm said Tuesday.

E&E's profits improved to $589,000, or 15 cents per share, from $518,000 or 14 cents per share, a year earlier, as the company held its indirect costs steady during the quarter.

E&E's net revenues rose by 8 percent to $20.5 million during the quarter that ended in July, compared with $18.9 million a year earlier.

Ronald L. Frank, E&E's executive vice president and chief financial officer, said the improved revenues were partly due to stronger sales at its Walsh Environmental subsidiary. Walsh's revenues jumped by 36 percent as energy-related work on mineral reserve and exploration analysis increased.

Sales from E&E's commercial clients, which account for slightly less than a quarter of the company's revenues, nearly doubled to $4.9 million during the quarter. Most of the increase was due to work on projects related to liquefied natural gas imports and wind energy, Frank said.

E&E, which got nearly 12 percent of its revenues during the fiscal year from work on relief efforts related to hurricanes Rita and Katrina, still is seeking more work in the Gulf Coast region, especially on projects related to damage to wetlands and coastal areas, Frank said.