** Shares of theater operators fall in premarket trading after President Donald Trump unveils 100% tariff on movies produced outside U.S.

** Cinemark Holdings CNK.N falls 5.6% to $28.59 and AMC Entertainment Holdings AMC.N down 0.4% at $2.67

** IMAX Corp IMAX.N falls 2.3% to $24.30

** American media stocks also tumbled after this announcement

** Barclays says it is not clear who will pay the tariff or how it will be calculated, given that U.S. studios are among the biggest producers of content globally

** Adds, "The immediate impact of this is likely to be that the aggregate production volume of content will fall globally"

** If "movie" is defined only as something in theaters, then studios will in effect be forced to follow Netflix's lead and limit theatrical releases - Barclays

** In Q1 2025, 44.7% of the content available from Amazon Prime Video AMZN.O, Apple TV+ AAPL.O, Disney+ DIS.N, Netflix NFLX.O and Paramount+ PARA.O was produced in the U.S., according to data from Gracenote, a content data business unit of Nielsen

(Reporting by Jaspreet Singh in Bengaluru)

((Jaspreet.Singh@thomsonreuters.com ; https://twitter.com/i_jass))