(Reuters) - Economic crises over the past two decades left the U.S. legal industry in better shape to deal with the turmoil of the COVID-19 pandemic, according to a senior Wells Fargo adviser who tracks and analyzes U.S. legal industry data.

After experiencing the economic crashes caused by the Sept. 11 attacks of 2001 and the Great Recession, many law firms had contingency plans when the pandemic hit, said Joe Mendola, senior director of sales for Wells Fargo Private Bank Legal Specialty Group.

He said that helps account for revenue growth the U.S. legal industry has managed to achieve during the pandemic so far. In a survey of 120 law firms released this week, Wells Fargo found that revenue has grown by 5.7% during the first nine months of the year, albeit unevenly.

Preparation "has a lot to do with the strong results," Mendola said. He said that some firms have diversified their practice areas; other law firm consultants have noted that firms have worked to avoid taking on major debt. Heading into the Great Recession, many firms had assumed large debts that helped precipitate layoffs and even collapse.

The Wells Fargo data is the latest indicator that in 2020, some law firms have not only weathered the pandemic's effects on the economy, but have even thrived.

Earlier this week, a joint report from Citi Private Bank's Law Firm Group and Hildebrandt Consulting, reviewing the past nine months, also found that the U.S. legal industry is on track for mid single-digit revenue growth.

Both the Wells Fargo and Citi reports found that the 50 largest U.S. law firms are seeing revenues rise faster than their smaller and more regional counterparts.

Demand has stayed relatively flat for the past nine months, which Mendola said he found to be "pretty amazing." Even as the pandemic has slowed down the courts, other practice areas such as bankruptcy have seen strong demand, he added.

The pandemic has created regional differences in the demand for legal services, Wells Fargo found. Major markets that are home to capital markets, restructuring services and technology and life sciences reported demand growing between 0.9% and 2.4%, the report said.

By contrast, other markets "with less exposure" to these practices, including Pennsylvania and Delaware, the Great Lakes, Texas, Florida and the Mid-Atlantic, all reported demand declining by 1.3% to 3.8%, Wells Fargo found.

The regional demand data isn't perfect, Mendola said, because large law firms have offices all over the country and Wells Fargo bases its geographic figures on the city where firms are headquartered.

Overall, he said he is bullish about the legal industry's financial prospects going into 2021, saying there is "pent-up demand" for trial and deal work.

"As the economy opens up to a more normalized situation, lawyers are going to be able to go back into the courtrooms," he said. "I feel good about looking at 2021, where the industry will be."