From Longman Business Dictionary
linkagelink·age /ˈlɪŋkɪdʒ/ noun1[uncountableU]COMMERCE a condition or restriction in a political or business agreement in which one country or company will only agree to do something if the other promises to do something in returnU.S. officials reject linkage as contrary to the WTO’s aim of free trade.
2[countableC, uncountableU] formal a connectionlinkage with/betweenThere no longer seems to be a very precise linkage between the two interest rates.
3[countableC, uncountableU]COMMERCE an agreement between two companies, countries etc to work togetherlinkage with/betweencalls for greater linkage with and support for local firms
Americans are suspicious of linkages between public schools and employers.