Shares of Arconic Inc. rose more than 4% with minutes to go before the end of the trading session after a Reuters report said the aluminum maker was putting itself on the auction block. Arconic, which was spun out of Alcoa Corp. in 2016, had announced it was selling its building and construction unit last month, and earlier this year announced a "strategy and portfolio review." Arconic is in talks with private-equity firms including Blackstone LP and Carlyle Group LP, according to the report, which cited people familiar with the matter.