The proposed changes would include two new grandstands, a redesigned pavilion, a state-of-the-art scoreboard, permanent floodlights and a new hotel. The capacity will increase from 15,000 to 25,000 for international matches.
Old Trafford will not stage a Test clash between England and Australia next summer, with Cardiff getting the nod, but it is hoped the city could host an Ashes Test in 2013.
The Red Rose county will begin work on turning the current square around by 90 degrees at the end of the 2009 season.
New media facilities and dressing rooms will be behind the bowler's arm, opposite the pavilion as it currently sits.
Lancashire and England all-rounder Andrew Flintoff, who was at the launch, said: "It looks lovely. One of the big things for me is keeping the pavilion.
"You go to some grounds around the world and they don't have any character, they are like football grounds, but this seems to have kept some of the old traditions along with bringing in some pretty radical buildings as well. I think it will look great.
"We need to get Test cricket back here as soon as we can. We need to make this a venue that can't be turned down. Once you get all that up, it will be impossible not to have games here."