LONDON — A jury in Britain on Tuesday convicted the brother of a suicide bomber who killed 22 people at an Ariana Grande concert in Manchester in 2017, finding him guilty on all 22 counts of murder for his role in planning and executing the attack.

The man, Hashem Abedi, was the brother of Salman Abedi, the man who detonated a vest laden with explosives, killing children, teenagers, and parents waiting to pick them up after Ms. Grande’s concert at Manchester Arena in northwestern England. More than 235 people were injured in the bombing, one of Britain’s worst recent terrorist attacks, and hundreds of others suffered psychological damage.

The jury took four and a half hours to find Hashem Abedi guilty on all of the murder charges, along with one count of attempted murder and one count of conspiracy to cause an explosion. A murder conviction carries an automatic life sentence, prosecutors said.

“Hashem Abedi encouraged and helped his brother knowing that Salman Abedi planned to commit an atrocity,” Max Hill, director of public prosecutions, said in a statement. “He has blood on his hands even if he didn’t detonate the bomb.”