Foreign investment in certain transport activities (e.g. the management of dining cars and sleeping cars of domestic and foreign railway companies by foreign companies when traveling from abroad through Austria or from abroad to Austria or vice versa, and the management of ship restaurants and buffets on watercraft of foreign shipping companies by foreign companies when traveling from abroad through Austria or from abroad to Austria or vice versa) may be subject to a reciprocity requirement. 
"§ 2.(1) This Federal Act shall not be applied to the activities listed in the following provisions, notwithstanding other expressly ordered exceptions by special federal provisions: [...]
15. the operation of railway companies and their ancillary facilities and their ancillary activities, including the operation of cable cars within the meaning of the Cable Car Act 2003, Federal Law Gazette I No. 103, in the case of reciprocity, the management of dining cars and sleeping cars of domestic and foreign railway companies by foreign companies for journeys from Abroad from Austria or from abroad to Austria or vice versa, the operation of shipping companies with watercraft, in the case of reciprocity, the management of ship restaurants and buffets on watercraft of foreign shipping companies by foreign companies when sailing from abroad through Austria or from abroad to Austria Austria or vice versa, the operation of ferries (ferries) and of motor transport companies;
16. the operation of air transport companies (air transport companies and aircraft rental companies), civil airport companies and auxiliary operations of air transport and civil airport companies; [...]" (Trade Regulations Act (BGBl. Nr. 194/1994),  last amended by BGBl. I No. 65/2020, § 2 (15) [google translation])
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"AUSTRIA [...]
ii) Investment in the transport sector (air transport services, road freight, taxis, buses) is subject to a reciprocity requirement; [...]" (OECD Code of Liberalisation of Capital Movements, Annex E).
Trade Regulations Act (BGBl. Nr. 194/1994),  last amended by BGBl. I No. 65/2020, § 2 (15) [google translation]
OECD Code of Liberalisation of Capital Movements, Annex E
[<a href="https://www.ris.bka.gv.at/GeltendeFassung.wxe?Abfrage=Bundesnormen&Gesetzesnummer=10007517">Act</a>],[<a href="https://www.oecd.org/investment/investment-policy/Code-capital-movements-EN.pdf">Code</a>]