Berg, who signed a three-year contract on October 31, oversaw his 10th match of the season on Boxing Day - a 1-0 defeat at Middlesbrough which saw them slip to 17th in the Championship table.
The result marked their fifth loss in six outings, while the former Rovers defender has managed to steer them to just one victory in his 57 days in charge.
The 43-year-old, who replaced the much-maligned Steve Kean, took the reigns ahead of their 2-0 defeat at Crystal Palace early in November but has done little to revive their fortunes since.
His time at Ewood Park has hardly been a happy one, with a statement released earlier this month playing down claims that he had stormed out of the club's Christmas party after an alleged bust-up.
Mark Hughes and Alex McLeish have become favourites to get the respective jobs at Blackburn and Nottingham Forest.
Former Rovers boss Hughes was immediately installed as the front runner to return to Ewood Park at 5/4 with Sky Bet after Henning Berg was sacked.
Roberto Di Matteo can be backed at 5/1 for this post while Tim Sherwood (7/1) and Billy Davies (8/1) are also names believed to be in contention.
Meanwhile McLeish has been backed in to odds-on favourite with Sky Bet to take charge at Forest following the sacking of Sean O'Driscoll on Boxing Day.
The Scot was installed as a 20/1 outsider for the post with Roy Keane (now 10/1) the early favourite, but heads the betting at 1/4 after attracting the majority of the early money.
Di Matteo also had a short spell as favourite on Thursday morning and is now available at 6/1.