Travel and tourism technology company Sabre Corp.'s shares slid 3.3% Tuesday, after the company said two of its biggest shareholders are selling 16 million shares. Units of private-equity firms TPG Global LLC and Silver Lake Management Co. are selling the shares at $24.55 a pop. The stock was last trading at $24.53. Sabre said it will repurchase 1 million of the shares using cash on hand. Goldman Sachs is sole underwriter on the deal. Sabre shares have gained 19.6% in 2018 so far, while the S&P 500 has gained 2.7%.