The 2012 Olympics will not harm a £4bn regeneration plan in Stratford City, east London, authorities have said.
The LDA said it was commitment to negotiations
The London Development Agency (LDA) is in talks with private landowners over acquiring land for the Olympic site.
But it has issued a compulsory purchase order of land covering the entire Olympic site in case talks broke down.
A private consortium, which owns land overlapping onto the Olympic site, said the order had placed the Stratford City project "at risk".
About 19% of the land required for the Olympic site still remains in private hands.
The LDA, which is preparing the Olympic site for development, is in negotiations with London and Continental Railways (LCR) over acquiring land under its control.
An LDA spokesman said LCR were covered by the purchase order because the Stratford City development lies right next to the Olympic Park site.
"They have land required as part of the Olympic Park and as with any landowner they are covered by the order," she said.
Culture Secretary Tessa Jowell said the compulsory purchase order was only to safeguard the land needed for the Olympic Park if negotiations with individual landowners broke down.
But she said she believed there was a "high level of commitment" in finding a negotiated settlement.
More than 100 shops, three big department stores, cafes, schools, hotels, parks and health centres are planned for Stratford City.