The Mayfair property has 236-bedrooms and has recently completed a £12.8m refurbishment.
It is also home to Michelin-starred Maze Restaurant, run by chef-patron Jason Atherton as part of the Gordon Ramsay stable.
The deal is expected to complete by September.
Strategic has also entered into an agreement to buy the 65% interest in the InterContinental Hotel in Prague for $68.8m (£36.7m) held by EU-Hotel, an affiliate of GIC Real Estate.
This will give it sole ownership of the luxury property in the city's old town area.
By Chris Druce