A group representing regional airlines says its president has stepped down and it will search for a permanent replacement.

The Regional Airline Association said Monday that Roger Cohen resigned effective immediately. Faye Malarkey Black, the group's senior vice president of government affairs, was named interim president.

The group did not give a reason for Cohen's departure, and a spokeswoman said the group would have no further comment.

Regional airlines operate smaller planes for the major carriers. Cohen had been president since 2006.

Cohen's background was in public relations, including at other aviation groups and TWA. Recently, he lobbied to reverse an increase in the number of flying hours needed to become an airline first officer, or co-pilot. The group says the rule has contributed to a pilot shortage.