[en] High-resolution laser-rf double-resonance spectroscopy has been performed in the 4f6 6s27F6 (4020.66 cm-1), 4f6 5d6s 9H2(11044.90 cm-1), 4f6 5d6s 9H3 (11406.50 cm-1), and 4f6 5d6s 7H3 (13542.80 cm-1) metastable levels of Samarium I. Hyperfine parameters have been deduced with an absolute accuracy of approx. 2 kHz. By means of laser-induced fluorescence, hyperfine constants have been determined in excited levels up to approx. 30560 cm-1, and isotope shifts measured for 11 lines