NEW YORK, United States —  Amancio Ortega, Europe's richest man and founder of retailer Inditex , had commercial property assets worth nearly €10 billion ($11 billion) at the end of 2018, up 11.5 percent from the previous year according to his investment firm on Wednesday.

Using the huge dividend payouts from Inditex, octogenarian Ortega has made largely debt-free purchases of buildings ranging from prime shopping real estate in London and New York to office buildings in central Madrid.

Most of Ortega's commercial holdings have been consolidated into a company called Pontegadea Inversiones which owns a 50.01 percent stake in Inditex alongside billions of euros in real estate investments.

Pontegadea's annual results showed real estate assets of €9.767 billion at the end of 2018.

Earlier this year, Pontegadea completed the purchase of two Seattle office blocks, currently leased to Amazon, in the Spanish fund's biggest-ever deal in the United States.

Pontegadea carried out real estate investments to the tune of €416 million during 2018 in addition to the purchase of 9.99 percent of Spanish telecommunications infrastructure company Telxius for €378 million, Pontegadea said.

Stripping out the Inditex shareholding, Pontegadea's revenues, mostly related to real estate activity, increased 5.2 percent on year in 2018 to €405 million.

Inditex announced a 17 percent dividend increase in March.

By Sonya Dowsett; Editor: Elaine Hardcastle