The phrase "area extending" is correct and usable in written English.
It can be used to describe a geographical or conceptual space that is broadening or increasing in size or scope.
Example: "The area extending along the riverbank has been designated as a protected wildlife habitat."
Alternatives: "region expanding" or "zone enlarging".
In Montana, the new launch sites were built in an area extending for some fourteen thousand square miles.
More recently, the Italian writers Mario Soldati and Attilio Bertolucci settled in the area, extending the literary tradition.
This term – standing for exclusive economic zone – means an area extending 200 nautical miles out to sea for China's sole economic use.
BEA is not the only company investing in real estate in Silicon Valley, an area extending south from just below San Francisco to San Jose.
Saturday: Minimal Resistance THE RED ZONE -- The area extending out roughly 100 miles from Baghdad is thought to be defended by Iraqs Republican Guard.
In the Changing UK study from Sheffield University in 2008, this area, extending into Headingley, stood out as the single worst area for social cohesion outside London.
It becomes apparent that what had appeared to be a full-service, modern marina was really a temporary staging area extending well into the harbor.
Those countries cover the area extending from Mauritania in the north to Congo in the south, and from Senegal in the west to Sudan in the east.
The main requirement is a site of considerable depth, rather than width, with a large area extending inland from the berths.
The district of High Peak includes the north Langdendale area, extending east from Tintwhistle, which belongs to the historic county of Cheshire.
They found a strong signal in the temporal lobe of the brain, an area extending roughly between the temple and the ear.
