Bjorn, the 2011 champion from Denmark, shot his second straight 66 to match Gallacher at 10-under 132. Spain's Miguel Angel Jiminez shot a 68 to join Englishmen Danny Willet, Tommy Fleetwood and Richard Finch and France's Victor Dubuisson at 9 under.
Jimenez, the 2010 champion, is making his 25th consecutive start in the tournament. He had five birdies in a six-hole stretch. Willett shot 64, Dubuisson 65, Finch 66, and Fleetwood 68.
Thirteen-year-old Ye Wo-cheng missed the cut with rounds of 78 and 76. The Chinese amateur became the youngest player in European Tour history in May at the China Open.