The synthesis of terminal hydroxyl-functionalized oligoethylene is achieved in a two-step one-pot method. Aluminum long chain alkyls (Al-PE) were generated by a catalytic chain transfer reaction involving iron 2,6-bis(imino)pyridyl ligation catalysts and methyl aluminoxane (MAO) aluminum alkyl precursors. At a high catalyst/cocatalyst ratio (>5 000) and a low ethylene pressure (1 bar) the chain transfer to aluminum is the dominant termination step. Discharging oxygen or dry air into the post polymerization reaction mixture leads to aluminum alkoxides (Al-O-PE) and after hydrolysis to hydroxyl-functionalized polyethylene (PE-OH). The degree of oxy-functionalization (up to 88 AE 3%) increased with increasing oxygen pressure and temperature and was more efficient with aluminum alkyls with a lower molecular weight.