Abstract: A gelled oil filling compound primarily intended for optical cables which meets the standard drainage test at 70.degree. C. and is stable to prolonged exposure at -40.degree. C. consists essentially of a low aromatic hydrocarbon oil and a block copolymer with a molecular weight in the range 200,000 to 2,000,000. The block copolymer comprises at least one segment tending to confer solubility in the oil and at least one segment tending to inhabit it, the preferred example being the polymer sold under the trade mark KRATON G1651 which has a center segment which is a random copolymer of ethylene and butylene and two end segments consisting essentially of styrene units.