Nexstar Media Group announced today it plans to acquire Tribune Media, in a $6.4 billion deal that would give Nexstar stations in eight of the 10 largest television markets, including New York, Los Angeles and Chicago, NPR reported. If approved by regulators, the purchase would give Irving, Texas-based Nexstar ownership or control of the most local television stations in the United States, with 216 stations in 118 markets. Nexstar’s present portfolio of stations includes WOI-TV and KCWI-HD in Des Moines. Tribune Media, which in August called off its planned acquisition of Sinclair Broadcast Group, currently owns 42 stations, including WHO-TV in Des Moines. Des Moines and the Quad-Cities are among 15 markets in which Nexstar and Tribune Media have overlapping stations. In a conference call with investors, Nexstar officials said today they would probably divest or swap stations in 13 of those markets. Shares of Nexstar were up 2.5 percent in mid-day trading.