CBS delivered quarterly earnings and revenue that surpassed analysts' expectations on Wednesday, but all its major segments, with the exception of cable, saw revenue declines.
Shares slid about 2 percent on Wednesday and continued their decline in early U.S. trading on Thursday. The stock was last down about 5 percent in pre-market trading. (How are CBS shares doing now? Click here to track the stock.)
The company also disclosed a $55 million restructuring charge related to cost-cutting measures in its radio and television station operations.
The media conglomerate posted second-quarter earnings of 74 cents per share, up 2 cents from a year ago, while revenue inched up about 1 percent to $3.22 billion, boosted by a 19 percent increase in cable network sales.
Affiliate and subscription fees grew 28 percent year over year, "driven by Showtime's distribution of the highest-grossing pay-per-view boxing event of all time," as well as 40 percent growth in retransmission fees from CBS-affiliated television stations, the company said in a statement, referring to the match between Floyd Mayweather and Manny Pacquiao earlier this year.
However, CBS' other segments—entertainment, publishing and local broadcasting—all saw decreases in sales, and advertising revenue fell 3 percent from a year ago, with content licensing and distribution sales decreasing 10 percent.
CBS said the decrease was mainly due to lower domestic television licensing sales, which were partially offset by higher international television licensing revenues.
Wall Street expected CBS to post earnings of 72 cents per share on $3.21 billion in revenue, according to a consensus estimate from Thomson Reuters.
The media giant late last month announced a quarterly dividend of 15 cents per share payable on Oct. 1. The sum remained unchanged from recent quarters.
CBS has worked to draw subscribers with on-demand television as consumer tastes shift. CBS recently launched a stand-alone streaming version of its premium cable channel Showtime for $10.99 per month.
It also last month said it would expand CBS All Access—its digital, video on demand and live streaming service—to about 75 percent of the United States through new affiliate agreements.
The move comes as more traditional media outlets try to adapt to the fast-changing media landscape and limit the negative impacts of cord cutting.
CBS' decision follows a similar one by Time Warner's HBO network, which recently announced an agreement with Verizon that would allow the carrier's Internet subscribers to access HBO Go without subscribing to a cable package.
HBO—a direct competitor of CBS' Showtime network—said the move is an attempt to adapt to changing consumer behavior and "bringing audiences the best in entertainment the way they want it."
CBS shares have fallen nearly 4 percent this year.
—CNBC's Jacob Pramuk contributed to this report.