Elon Musk and Twitter will go to trial over their $44 billion deal in October.

Twitter and Elon Musk will go to trial in October over whether the billionaire must complete his $44 billion acquisition of the social media company, a Delaware judge ruled on Tuesday.

The ruling was the first decision in a lawsuit that Twitter filed this month to force Mr. Musk, the world’s richest man, to go through with the blockbuster deal. Mr. Musk had agreed to buy Twitter in April, but indicated this month that he wanted to terminate…