Jim Ratcliffe, the billionaire co-owner of the soccer club, framed plans for the 100,000-seat venue as crucial to the British government’s plan to revive the northern English city.

Manchester United may be experiencing one of the most chastening seasons in its recent history, but the club is planning for a much brighter future.

LONDON — Manchester United unveiled plans on Tuesday to build the “world’s greatest” soccer stadium. A proposed 100,000-seater arena, costing around 2 billion pounds ($2.6 billion), would be built next to United’s current Old Trafford home and surpass Wembley Stadium as the biggest in the United Kingdom.