Cablevision Systems declined after a $61 million charge to extinguish debt and the defection of video subscribers helped fuel a surprise third-quarter loss. Cablevision, which has 3 million customers on the East Coast, has struggled to gain video subscribers as it competes with Verizon Communications’ FiOS. Cablevision’s rising capital expenditure has crimped profit as spending on plants and operations jumped 41 percent this year. The company reported a third-quarter loss of $3.8 million from continuing operations, or a loss of 1 cent a share, compared with a profit of $39.3 million, or 14 cents, a year earlier. The average analyst estimate forecast profit of 16 cents per share, according to Bloomberg. It lost 10,000 video customers in the period, and added 28,000 Internet customers.