CoStar reports that Westfield Group has entered into a joint venture agreement with O’Connor Capital Partners covering six of its regional malls across Florida. O’Connor’s investment will equal a 49.9 percent interest stake in the portfolio following a series of transactions with a gross value of $1.283 billion. The price O’Connor will pay is equal to Westfield’s book value. Westfield Group will remain as property, leasing and development manager at the six properties, which include Westfield Brandon,…