All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
There is no doubt that describing someone other than Allaah as the owner of the world is a statement that makes a person associate partners to Allaah, as it is Allaah Alone who owns this world. Allaah says (which means): {And to Allaah belongs the dominion of the heavens and the Earth and all that is between them, and to Him is the return of all.}[5:18].
Since you did not intend the reality of that expression, then we hope that you are not sinful. The kind of Shirk that Allaah does not forgive is the major Shirk if someone dies persisting on it. Allaah says (which means): {God does not forgive (the sin of) joining other gods with Him; but He forgives whom He pleases other sins than this.}[4:116].
However, if one repents from Shirk whether small Shirk or major, Allaah will forgive him and accept his repentance. Allaah says (which means): {Say: 'O My slaves who have transgressed against themselves (by committing evil deeds and sins! Despair not of the mercy of Allaah; verily, Allaah forgives all sins. Truly, He is Oft-Forgiving, Most Merciful'.}[39:53].
Allaah knows best.