Extra Region Sudoku 2013 - 1

The Daily League, comprising of Tom Collyer, Fred Stalder, Prasanna, Seungjae Kwak(no link available as yet), and myself as authors kicked off yesterday. My Consecutive sudoku was the opening puzzle and Tom C has created todays Anti-Knight. This is our small way of getting all bloggers at one spot to enjoy each others puzzle in a friendly competitive fashion.

In continuation of my puzzles, here is a medium level Extra Region Sudoku for you all.

Rules of classic sudoku apply. Additionally, each of the marked regions contain digits 1 to 9 without repetition.