Speaking to the press after meeting Covic and informing him of the measures he had decided to take, Ashdown said this had been perhaps the most difficult decision he had to make in his term.
Ashdown said he had been trying to persuade Covic to step down until the last minute, but that the Bosnian Croat persisted in refusing, which prompted Ashdown to dismiss him in accordance with his so-called Bonn powers as the only possible solution.
Unlike similar cases in the past, the dismissal will not mean the end of Covic's political career. Ashdown said Covic could continue to be active in his party and could even return to the executive authority if he proved his innocence in court.
Ashdown said he was very sorry because Covic had done well in the Bosnian Presidency, helping reforms in his country and party -- the Croatian Democratic Union of Bosnia-Herzegovina.
The High Representative said the dismissal had been inevitable because it was a question of principle. He added stepping down was expected of every person in the executive authority who had been indicted.
Ashdown said the same principle would be applied to Bosnian Transport and Communications Minister Branko Dokic. The court in Banja Luka today confirmed an indictment charging him with abuse of office and power.
The same principle was applied against the state Presidency's ex-Serb member, Mirko Sarovic, who resigned in 1993, and against former treasury minister Mila Gadzic.
Ashdown said he would not interfere with the status of Constitutional Court president Mate Tadic who, together with Covic and five other men, has been charged with abuse of office and taking bribes.
The Constitutional Court has refused to suspend Tadic with the explanation that a judge could be replaced before the end of his term only if he was convicted.
Ashdown said it was up to the court to decide how it would protect its integrity, and added that he did not intend to interfere with the work of courts.
Covic, Tadic, four Ivankovic-Lijanovic brothers and university professor Zdravko Lucic are expected to appear before the Court of Bosnia-Herzegovina to enter pleas. They have been indicted by the State Prosecutor's Office department for corruption, organised and white collar crime.
The state Parliament's lower house is expected to take steps to choose Covic's successor in the coming days. Under the Constitution, his successor will come from the lower house and be from the Bosnian Croat people. Martin Raguz, the deputy chairman of the lower house, is the likeliest candidate.
Covic said the decision to replace him was illegal and against the Constitution, but did not say if he would refuse to comply with it.
"Those who made this decision and rigged this trial will end their mission, and it is our obligation to build the country to fit all the constituent peoples and citizens," Covic said in a written statement delivered to the media.
He added he believed the decision to replace him would be the last of its kind brought "contrary to (Bosnia's) Constitution and laws".
Last week he told the press he would not resign but said he would respect the international community's decisions "whatever they might be".