J.Th. Ladenius (1944) worked from 1966 to 1973 for contractors Wilma in Weert. In 1973, he developed two large housing projects in the South of the Netherlands with Planomij B.V. From 1974 to 1980, he worked as a property developer for Westland/Utrecht Projectontwikkeling.
In 1980, he joined the Nederlandse Credietbank as director of property. Following the takeover of this bank by Chase Manhattan Bank in 1986, he set up Ladenius Projektontwikkeling B.V. He developed a range of housing and office projects up to 1995, when he began to focus principally on advising and supporting foreign and other investors in the area of the acquisition of good, leased immoveable property.
From 1995 to July 2005, he also helped set up and manage the property partnerships AKRONned I through VII. Virtually all of these partnerships have now been sold, with favourable results.
In February 2004, he set up APF International, together with drs. K. Streefkerk.