Here is the key word: "calleth"
Rom 9:11 (For the children being not yet born, neither having done any good or evil, that the purpose of God according to election might stand, not of works, but of him that ** calleth;) **
The calling of God is a Sovereign act - He calls whom He will and He does not call all.
Just as Jesus said - no man comes unto me unless the Father draws him.
Not all who are called are chosen. Being called is not being chosen (elect) Only those who are called are given the power to choose to believe and obey. Those who love God with their whole heart, mind and soul become the chosen and receive eternal life.
Once we see this outline of the calling and choosing process through testing the Scriptures make perfect sense. NO ONE TRULY HAS FREE WILL UNTIL CALLED AND EMPOWERED.
"Many are called but few are chosen" Jesus
"Make your calling and election (being chosen) sure" Peter
The Calvinist error is to insist that all who are called are also elect (chosen).
The Armenian error is to insist that all are called (and have free will) but not elect.
As is often the case the truth lies in the middle... God calls whom He will and once called they have free will.