By Sarah N. Lynch

WASHINGTON (Reuters) - Gregg Berman, an equity market structure expert who helped develop a new system for collecting critical trading data, is set to leave the U.S. Securities and Exchange Commission later this month, the agency said on Wednesday.

Berman, an associate director in the Trading and Markets Division, joined the SEC in 2009. He now oversees a unit he helped create called the Office of Analytics and Research.

He first distinguished himself for his work in analyzing the causes of the "flash crash" on May 6, 2010, when the Dow Jones industrial average plunged about 700 points before sharply rebounding.

Berman and other regulators worked to collect data from the event and were able to determine that a mutual fund's algorithm helped trigger the downward spiral after it executed a large sell order of the e-mini Standard & Poor's 500 futures contract.

Later Berman advocated for the SEC get better and quicker access to trading data to make it easier to analyze events across the fragmented marketplace.

He helped develop new rules to create a consolidated audit trail that, once completed, will give the SEC access to every trade order, execution and cancellation so it can better police the market.

He also led the charge for implementing the SEC's Market Information Data Analytics System, or MIDAS, which collects time-stamped records down to the microsecond from the same proprietary stock feeds used by high-speed trading firms.

The SEC has been using this new tool both to inform its policies for equity markets and to provide the public with more data about the functioning of the marketplace.

His work at the SEC is well-known in the industry, and he is a frequent speaker at conferences on equity market structure issues such as high-frequency trading.

The SEC did not say where Berman plans to go next. Before working there, he was a co-founding member of the RiskMetrics Group in New York.

(Reporting by Sarah N. Lynch; Editing by Lisa Von Ahn)