Starwood Hotels & Resorts Worldwide is to expand its portfolio of hotel spas, with more than 150 either new or planned for the coming year.

The move will also see three of its brands gaining their own exclusive in-house spa product.

Of these, Shine Spa for Sheraton made its debut at the Sheraton Full Moon Resort & Spa in the Maldives in 2009. More than 15 are expected to be open by the end of 2011.

Iridium Spa, designed exclusively for St. Regis, is to debut at The St. Regis Lhasa Resort in Tibet in December with others to follow in 2011.

Explore Spa by Le Meridien will debut early in 2011 at Le Meridien Oran in Algeria and Le Meridien Pyramids in Egypt, with other conversions and new builds in development.

Elsewhere, Heavenly Spa by Westin will double its 20 existing sites in the next two years, while Away Spa by W Hotels will grow from five to 15 spas in the next few years.

Starwood is also continuing its partnership with Steiner Leisure, with 17 Bliss spas and 10 Remède spas operating at its hotels and several more in development.