The Subway restaurant chain has opened more than 500 restaurants encompassing about 600,000 square feet of retail space in the final months of 2010, National Real Estate Investor reported.

The Milford, Conn.-based company, which has more than 33,700 locations worldwide, continues to expand as it implements a greater number of prototype café stores, which are typically located in office buildings.

“The month of December isn’t over yet,” said Subway spokesman Les Winograd. “We’re still opening restaurants.” He said the restaurant’s newest outlets average about 1,200 square feet each.

Subway, which in 1984 opened its first overseas location in the Middle Eastern nation of Bahrain, now has more than 9,000 individually owned-and-operated restaurants outside the United States.

The chain has 500 restaurants in Brazil and 50 locations in Malaysia. Subway has 2,400 locations in California, more than in any other state.