A process for converting gaseous alkanes to liquid hydrocarbons wherein a gaseous feed containing alkanes is reacted with a dry bromine vapor to form alkyl bromides and hydrobromic acid vapor. The mixture of alkyl bromides and hydrobromic acid are then reacted over a synthetic crystalline alumino-silicate catalyst, such as a ZSM-5 zeolite, at a temperature of from about 150.degree. C. to about 400.degree. C. so as to form higher molecular weight hydrocarbons and hydrobromic acid vapor. Hydrobromic acid vapor is removed from the higher molecular weight hydrocarbons. A portion of the propane and butane is removed from the higher molecular weight hydrocarbons and reacted with the mixture of alkyl bromides and hydrobromic acid over the synthetic crystalline alumino-silicate catalyst to form C.sub.5+ hydrocarbons.