The 27-year-old will be able to once again play alongside his indentical twin brother David, who has agreed to stay at the club until the end of the 2007 season.
march was one of the five players released by the Giants earlier this week having joined the club in 2002.
He made ninety Super League appearances before picking up a knee injury earlier in the season.
Wildcats chief executive Steve Ferres said: "Paul is a quality addition to the squad; he has great Super League experience and can operate in a number of pivotal positions.
"David has been one of the club's most consistent performers for over ten years, and it will be great to reunite the two brothers as they seem to pull the best out of each other."