** Shares of memory chipmaker Micron Technology MU.O rise 4.% to $71.1 premarket
** MU notifies its U.S. customers, which includes iPhone maker Apple AAPL.O, that it plans to impose a surcharge on some products from Wednesday to account for U.S. President Donald Trump's new tariffs, Reuters reports, citing four sources familiar with matter
** Trump's tariff announcement last week applied to memory modules and solid-state drives but exempted semiconductors, which account for part of Micron's portfolio
** Samsung Electronics 005930.KS, which competes with MU, said on Monday it sees Q1 operating profit of 6.6 trillion won ($4.49 billion) above analysts' estimate of a 5.1 trillion won as looming tariffs spur memory chip sales and smartphone demand
** Up to last close, MU stock had fallen ~19% YTD
(Reporting by Priyanka.G in Bengaluru)
((priyanka.g@thomsonreuters.com;))