"He is a player who has given us good service and we are pleased to keep him at the club a bit longer," Rovers boss Paul Trollope told the club website.
"We hope Mikkel can produce the performances we know he is capable of over the next few months."
Andersen is currently away on international duty but Rovers hope to get him back in time for Saturday's match against Oldham.
Source: BBC Sport
Source: BBC Sport