NOVELTY - A heavier hydrocarbon fraction is separated from gaseous hydrocarbon feed by subcooling a first liquid stream. The subcooled stream is expanded and passed to a fractionation column. A separated lights fraction of the feed is cooled by transferring heat to the expanded stream, and is introduced to upper part of the column. The heavier hydrocarbon fraction is recovered as bottom fraction.    USE - The method is for separating heavier hydrocarbon fraction from gaseous hydrocarbon feed. The heavier hydrocarbon can be ethane from natural gas and/or olefins, e.g. ethylene, from gases in petroleum refining or petrochemicals manufacture.    ADVANTAGE - The first liquid stream and separated lights fraction with the expanded stream are heat-exchanged against the evaporating stream from the subcooled stream, thus producing a stream of low temperature that leads to reduced overheads temperature and increased recovery.    DETAILED DESCRIPTION - Separation of heavier hydrocarbon fraction from gaseous hydrocarbon feed involves cooling the feed to produce a partially condensed stream. The produced stream is separated into first liquid stream and first gaseous stream. At least a portion of the liquid stream is subcooled, expanded, and passed as a liquid feed to a fractionation column. A separated lights fraction of the feed is cooled to produce a cooled stream. The heavier hydrocarbon fraction is recovered as a bottom fraction. At least a portion of subcooling required in subcooling step is provided by transfer of heat to the expanded stream. At least a portion of cold required to cool the separated lights fraction to produce the cooled stream is provided by transfer of heat to the expanded stream. At least a portion of the cooled stream is introduced to an upper part of the column. An INDEPENDENT CLAIM is also included for an apparatus for separating a heavier hydrocarbon fraction from gaseous hydrocarbon feed, comprising first conduit for transferring the first liquid stream to a first heat exchanger, mechanism for expanding the subcooled stream, second conduit for transferring at least a portion of expanded stream to the second heat exchanger, and third conduit for introducing cooled stream to an upper part of the column. At least a portion of the cold required to cool the separated lights fraction is provided by transfer of heat to the expanded stream.