Brad Miller, general manager of the Des Moines Area Regional Transit Authority (DART), will leave the bus service in July, DART announced today.

Miller has accepted an offer from the Pinellas Suncoast Transit Authority in Pinellas County, Fla., to become its next CEO. His last day at DART is expected to be at the end of June.

Miller took over at DART in July 2006 as the first general manager after the system transformed from the former Metropolitan Transit Agency. He leaves as the transit authority prepares to put together plans for its DART Forward 2035 long-term planning project. Miller oversaw the completion of funding for a new $21 million transit hub to be built downtown.

DART will begin conducting a national search to replace Miller soon after the regular DART Commission meeting on April 26. Elizabeth Presutti, the agency’s chief development officer, is expected to be named interim general manager, according to a DART press release.

Miller said in the release that the decision to leave was difficult. The Florida agency he will take over operates a bus system that has about three times the ridership of DART.