Globalization is illustrated in aviation by commercial, marketing and technical alliances amongst airlines, in some cases involving ownership and control issues beyond national boundaries, while transnationalization means airlines going '.........', that is locating parts of their operations outside their national base.

One factor affecting civil aviation is the emergence of regional and sub-regional blocs, which provide ......... for sharing of some of the safety responsibility in a common localized geographic approach.

Another factor is the ......... of sectoral boundaries: developments in economic activity have led to a lessened distinction between the boundaries of responsibilities of regulatory authorities at national, regional and global levels alike.

This can lead to ......... of labour, competition and, most importantly, safety regulation, in the absence of adequate safeguards, particularly when the international dimension is added.

One very significant trend in recent years is the commercialization of service providers, including the handing over of airport and other air navigation facilities and services by governments to ......... authorities or even to the private sector.

The commercialization of such provision therefore necessitates both ......... delegation of operational functions of governments and changed regulatory functions of governments.

Civil aviation is unique in that it remains regulated at the international level largely by ......... agreements between governments, but several regional and subregional air services agreements are already in place and others are under consideration.

Economic liberalization is being ......... transnationally by the Organization for Economic Co-operation and Development as well as globally by the World Trade Organization which is responsible for the General Agreement on Trade in Services.

A factor which is having an increasing impact on civil aviation, and one which is likely to grow in importance in the future is environmental ..........

There is increasing recognition of and response to environmental concerns, and a perception that the aviation sector may be contributing ......... to both existing and emerging problems.