Morgan Sindall has started work to redevelop Lancashire County Cricket Club's ground, while Tesco plans to be on site with its 100,000 sq ft store nearby on Chester Road later in the year.
The cricket club won a Court of Appeal decision at the start of July which dismissed a judicial review plea from Albert Gubay's development company Derwent Holdings against Trafford Council's approval of the club's ground redevelopment plans.
Jim Cumbes, chief executive of Lancashire County Cricket Club, said: "It's with great joy and some relief that we get started on the major work to demolish the old stands and build the world-class ground we have been striving for. After seven years of hard work and tough battles, we can say the future for the club is now brighter.
"Derwent's legal challenge seemed to us a pointless exercise, but it did create huge uncertainty due to its financial implications."
The club implemented its legal planning consent by moving ahead with the installation of four new 53-metre high floodlights, which was completed before England's Twenty20 match with India last month.
New contractors Morgan Sindall are now starting work on a development programme which the club believes will transform Old Trafford into a venue fit to host the 2013 Ashes.
The club has submitted its bid to the England & Wales Cricket Board for the right to stage Test cricket and said it should hear a response at the end of September.
Contractors will have to work round the crowds attending a full county cricket programme, a Twenty20 match against South Africa and a one day international with Australia in the summer.
Cumbes added: "The aim of this project was to bring back the Ashes to Old Trafford in 2013. Now we can start improving our chances of turning that dream into reality.
"The club would like to thank all the people who supported us, from local residents, to our members and supporters, and cricket-lovers from all over the world."
The £32m development is part of the overall plans being led by Ask Developments, which includes the Tesco store fronting Chester Road near to the ground.
LCCC is investing in new pitches, stands, player and media facilities and an extension to the ground's indoor cricket school and public areas. Two new grandstands and a refurbished pavilion will ensure a capacity of 15,000, capable of rising to 25,000 with temporary seating, and a screen showing action replays.
Matthew Magee, Tesco corporate affairs manager, said: "Our flagship store for Greater Manchester is another step closer, and we can start to plan the huge recruitment drive for the new staff we'll be employing as we look towards getting on site ourselves later in the year."
In July this year, the Manchester studio of architectural practice BDP started work on phases two and three of the redevelopment of the ground.
BDP designed the first phase, The Point, a £12m conference and events venue which was completed and opened in July 2010.