Luiten had three birdies on each side Friday in getting to 11-under 133 for the tournament. Eduardo De La Riva (65 Friday), Callum Macaulay (66) and Paul Waring (67) are tied for second at 10-under.
Hennie Otto matched De L Riva's 65 and is tied with Romain Wattel for fifth at 8-under.
First-round leader Tom Lewis ended up at 2-over in the second round and is among those tied for seventh, four strokes behind Luiten.
Luiten, starting on the second nine of the Diamond Country Club course in Atzenbrugg, opened birdie-bogey but got to 2-under on the day with birdies at Nos. 13 and 16 before an 18th-hole bogey dropped him to 1-under at the turn.
He came back with a birdie at the first hole while birdies at 4 and 7 pulled him clear of the field.