McLean-based Hilton Worldwide plans to open two new hotels in Europe in the cities of Warsaw and Lodz, Poland.

Hilton said Monday that the properties will open by the end of 2012. Both are within the Doubletree by Hilton brand. The Doubletree by Hilton Warsaw Conference Centre and Spa will be operated by Polaris Hospitality Enterprises, and the Doubletree by Hilton Lodz will be operated by Film Hotel.

Hilton said that Poland is one of its key European growth markets. The company currently operates one property in Poland, the Hilton Warsaw Hotel and Convention Centre, and six others in development: two full-service hotels in Gdansk and Wroclaw, and four Hilton Garden Inn properties in Warsaw, Wroclaw, Rzeszow and Krakow.

Hilton has more than 3,600 hotels in 81 countries. There are 220 Doubletree by Hilton properties, including 12 in Europe.