** Shares of drugmaker Merck MRK.N rise 5.81% to $117.40 premarket
** Co posts smaller-than-expected Q1 loss on an acquisition-related charge that outweighed the 5% increase in product sales
** Reports Q1 adj. loss of 1.28 a share, while analysts expected a loss of $1.51 a share, according to LSEG-compiled data
** Expects 2026 profit of $5.04 to $5.16 per share compared with previous estimate of $5 to $5.15 per share
** Q1 revenue rose to $16.3 billion from $15.5 billion a year earlier and was above estimates of $15.8 billion
** Up to last close, stock up 5.4% YTD
(Reporting by Sneha S K)
((Sneha.SK@thomsonreuters.com;))