Starwood Hotels & Resorts will open more than 40 new properties across Europe in the next five years.
Today's announcement represents a portfolio increase of almost 30 per cent.
The group will open five new hotels in Turkey by the end of this year, including the launch of the St Regis brand in Istanbul.
Russia will see two new Starwood hotels in 2015, Sheraton Ufa and a Four Points by Sheraton in Kaluga, the brand's entry into the country. Six more hotels in Russia are also in the pipeline.
In Germany, the Aloft brand will debut in Stuttgart and Munich this summer, while The Netherlands will see the introduction of the W and Element brands by the end of the year.
In southern Europe, three Sheraton hotels will open — Sheraton Bucharest, Sheraton Lake Como Hotel, and Sheraton Dubrovnik Riviera Hotel.
In total, by the end of 2017, more than 15 new openings will take place across the mid-market Aloft, Four Points by Sheraton and Element brands.
A statement said: "Aloft will more than double its portfolio in Europe with hotels opening in St Petersburg and London over the next two years, in addition to two hotels in Germany, opening this summer. Four Points by Sheraton will also expand in emerging markets with eight openings planned in Turkey and Russia by 2017.
"The eco-centric Element brand, introduced to Europe with the opening of Element Frankfurt Airport Hotel last year, will debut in Amsterdam before year-end, and become part of an Aloft and Element dual-hotel development in the historic Tobacco Dock section of east London in 2017 (see news, June 2014)."
Michael Wale, president of Starwood Hotels & Resorts in Europe, Africa and the Middle East, said: "The record growth experienced in the last five years in the mid-market segment has set the stage for 2015, where we will see a vigorous expansion in mature and emerging markets.
"The increasing demand for conversion and franchise deals from new and existing partners is a strong reflection of Starwood's powerful network, loyal customer base and commitment to deliver value for owners."