The Spanish billionaire took the holding in Enagas through his investment vehicle Pontegadea, which took part in an Enagas capital hike, buying shares worth 282 million euros (£242.26 million) according to Reuters calculations.
Enagas raised fresh capital after U.S. gas pipeline operator Tallgrass Energy accepted a $6.3 billion offer from a consortium of which the Spanish energy group is part.
Ortega's Pontegadea owns a 50.01% stake in Zara fashion store owner Inditex, as well as investments worth billions of euros in prime office and shopping districts. These are largely debt-free purchases using dividend payouts from Inditex.
Pontegadea has bought infrastructure assets in the past, including a 10% stake in Telxius, which owns telecommunication towers and submarine fibre optic cable, in 2018.
Ortega's investment arm recently bought The Post Building in London, which houses McKinsey's UK headquarters, for 600 million pounds ($770 million).
(Reporting by Sonya Dowsett, editing by Inti Landauro and Alexander Smith)
