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CDW Corp (CDW - Get Report) shares were indicated sharply higher in pre-market trading Wednesday after the IT solutions group was tabbed to join the S&P 500 next week.

CDW will replace Total System Services Inc. (TSS) in the benchmark, S&P Dow Jones said, with the change effective at the start of trading on Monday September 23. CDW, which earns more than half its revenues from small-to-medium-sized businesses, had net sales of $4.63 billion over the three months ending in June, its fiscal second quarter, and earned $196.6 million in net income.

 "We delivered excellent topline growth and profitability in the quarter while continuing to invest in the future and deliver shareholder value," CEO Christine Leahy said at the time. "These results reinforce the strength of our strategy and power of our business model - underpinned by balanced performance across our customer end markets, the breadth of our products and solution portfolio and the ongoing execution of our strategy for growth."

CDW shares were marked 6.4% higher in pre-market trading Wednesday to indicate an opening bell price of $121.10 each, a move that would extend the stock's year-to-date gain to around 50% and give the Linconshire, Illinois-based group a market value of around $17.5 billion.

TSS shares were indicated 0.62% lower at $132.45 each.