Tree suppliers can now register online to supply the trees through Olympic supply chain website www.competefor.com.
The four to seven metre high trees will be planted over the following three winters and the winning suppliers will be announced in the spring.
Trees will include a range of traditional species such as oak, ash, alder, willow, birch, hazel, cherry, poplar, London plane and lime.
The Olympic Delivery Authority (ODA) will also be seeking suppliers for thousands of younger woodland trees shrubs and other plants over the coming years.
ODA project sponsor for parklands and public realm John Hopkins said: "Trees will create the roots of the London 2012 Olympic Park.
"We are planting trees that reflect great British parks but also create habitats for wildlife and help ‘future proof' the park and surrounding built-up areas against climate change and flooding.
"Trees will help manage flood and rain water in the park, create a "cool island" on hot days and protect people from strong sun and winds."
The opportunity has been advertised on www.competerfor.com by Bam Nuttall, the contractor appointed to manage the delivery of the northern section of parklands.
More than 60 tree suppliers are already registered on CompeteFor following an industry day in spring 2007.
Further contract packages and a contract for the landscape of the south of the park will be issued in 2009.