Guerrier is the only player in the field yet to drop a shot after adding a 65 to his opening 68 to finish nine under par, a total later matched by joint overnight leader Bjerregaard, who returned a 68.
The English duo of Steven Brown and Ryan Evans are a shot off the pace after rounds of 66 and 69 respectively, with France's Mike Lorenzo-Vera another stroke back after a superb 64, the lowest score of the week so far in Sicily.
Guerrier regained his playing privileges via the Challenge Tour last season and is already on course for his best season on the European Tour thanks to finishing third in the NBO Oman Open and another top 10 in the Spanish Open.
"I'm playing really good," the 32-year-old said. "I made no bogeys so, in these conditions, in two rounds, to make no bogeys is really good.
"I come from La Rochelle where it's very windy so I think it helped me a lot. I also won the Amateur Championship (at Royal St George's in 2006) so I think I like the windy conditions but it's just two rounds. There are two more rounds so the road is long."
Bjerregaard held the outright lead after recovering from a bogey on the third with five birdies, but bogeyed the 16th as strong winds again made conditions more difficult for the later starters.
"It feels good, it was a battle out there," Bjerregaard said. "Everything from hitting the fairway to five-foot putts are really tough so I'm very happy with my game today.
"I got off to a slow start, didn't make birdie on two and four which you pretty much have to - especially in these conditions - so I got a little bit worried, but took advantage of some of the tougher holes and all in all I'm very pleased.
"It feels like this is a place where a lot can happen, there's a lot of golf left but I'm gaining confidence every day I'm playing like this. It's not been great so far this year but I'm starting to play a bit better and I'm just taking it all in and gaining a lot of confidence."