Baltimore Mayor Catherine Pugh resigned under pressure Thursday after revelations that she made more than $500,000 selling her children’s book series to entities that do business with the city.

Steven Silverman, Pugh’s attorney, announced her resignation effective immediately at an afternoon news conference.

Reading from a written statement from Pugh, Silverman quoted her as saying, “Baltimore deserves a mayor who can move our great city forward.”

The first-term Democrat, who became mayor in late 2016, is the subject of state and federal investigations.

Maryland Gov. Larry Hogan, a Republican, and several of her fellow Democrats had called on Pugh to step aside after The Baltimore Sun reported on her book deals, which raised conflict-of-interest concerns and may lead to criminal charges.

“This was the right decision, as it was clear the mayor could no longer lead effectively,” Hogan said in a statement.

Pugh, whose term runs until December 2020, had been on paid leave since April 1 for health reasons. Bernard "Jack" Young acted as her interim replacement and automatically becomes the permanent mayor without having to be sworn in.

“I am sorry for the harm that I have caused to the image of the city of Baltimore and the credibility of the office of the mayor,” Pugh, 69, said in her written statement.

At issue are the sales of Pugh's "Healthy Holly'' books to the University of Maryland Medical System, where Pugh was a member of the volunteer board of directors until resigning that post last month.

The medical system paid Pugh $500,000 for copies of the self-published books while she served on its board, according to the Sun. The books are aimed at promoting exercise and good diet.

Health insurer Kaiser Permanente also bought books – when the city spending board Pugh controls awarded the company a $48 million contract to provide health insurance to city employees, the Sun reported.

Pugh apologized for the book scandal in March but said she "never intended to do anything that could not stand up to scrutiny." She called her deal with the medical system "a regrettable mistake."

On April 1, Hogan directed the state prosecutor's office to investigate Pugh’s financial dealings with the medical system. Last week, FBI and IRS agents executed a search warrant and seized records from Pugh’s office, two homes and a nonprofit group linked to her.

Young said his government will focus on providing essential services.

“Although I understand that this ordeal has caused real pain for many Baltimoreans,'' Young said in a statement, "I promise that we will emerge from it more committed than ever to building a stronger Baltimore.”

Contributing: Doug Stanglin, USA TODAY; The Associated Press