Arconic Plunges After Walking Away From Apollo’s Buyout Offer

Arconic Inc. tumbled the most in eight months as the board rejected a sale of the company, scuttling a highly anticipated deal that would have ranked among the biggest leveraged buyouts since the global financial crisis.

Apollo Global Management had been in talks to buy the maker of aerospace and auto parts for $22.20 a share, valuing Arconic at about $10.7 billion, according to people familiar with the matter. The private-equity firm had secured financing for the offer, which included coverage of potential liabilities related to London’s deadly 2017 Grenfell Tower fire, the people said.

The collapse of the negotiations ...