** Medical device maker Solventum's SOLV.N shares rise 1.8% to $77.67 premarket
** Co says Thermo Fisher TMO.N will buy its purification and filtration business for about $4.1 billion in cash
** The transaction is expected to be completed by the end of 2025
** Up to last close, SOLV down 4.7% since close on March 26, 2024, after spin off from 3M
(Reporting by Puyaan Singh)
((Puyaan.Singh@thomsonreuters.com;))