Oxford Properties is partnering with Brookfield Office Properties to develop the City site London Wall Place EC2.

The real estate arm of Canadian pension fund Omers is entering into a 50:50 joint venture with New York-listed Brookfield for the site – earmarked for a 500,000 sq ft office scheme designed by Make Architects.

Property Week understands the deal will complete on 12 July.

Brookfield agreed a deal with landowner the City of London Corporation to secure an option on the £350m site just 24 hours after rival developer Hammerson’s long-standing option expired. Hammerson won approval from the City last summer to build a 300,000 sq ft office block and 195,000 sq ft tower on the site.

However, following the sale of Hammerson’s other City assets to Brookfield last month for £520m, the developer said it intended to allow the option with the City of London to lapse by 28 June 2012 as the scheme did not provide sufficiently high returns for the company.

Under the new joint venture arrangement, Oxford will initially invest £10m into the deal – representing half the cost of the option – and fund 50% of the project’s development cost.

The partners are not expected to lodge new plans, but minor “value engineering” changes to the scheme could be made.

Oxford also has a 50:50 joint venture with British Land to develop the 610,000 sq ft “Cheesegrater” Leadenhall Building in the City.

Oxford and Brookfield declined to comment until next week when the deal is expected to complete.