The phrase "diminished demand for" is correct and can be used in written English.
It is a common idiom used to describe a decrease in the demand for a product or service. For example, "Due to economic instability, there has been a diminished demand for new cars."
The low effect reflects the advertisers' disenchantment with the ads and diminished demand for them.
An important reason for the widening gap between imports and exports is sharply diminished demand for American products in Asia.
The recent turmoil in Asia has diminished demand for oil in what used to be the fastest-growing energy market in the world.
As for Google, Mr. DelBene said it has not "in any way diminished demand" for Office because Microsoft's applications are "just so far beyond the capabilities that are in those alternative products".
Moreover, the tactics Sessions supports have not diminished demand for narcotics in the U.S., and it is that demand which guarantees we will continue to have drug trafficking.
In the Apr. 12 issue this year, for instance, I spotlighted Hartmarx, which has suffered from the business-casual trend that has diminished demand for men's suits.
A lower dollar would tend to diminish demand for securities denominated in dollars.
First, a rapid slowdown in the euro-zone economy is diminishing demand for emerging-world exports.
He said the cuts were brought on by a diminishing demand for the nonprofit company's services.
Docks once jammed with shipping containers showed gaps between the stacks, reflecting diminishing demand for Asian-made furniture and clothing.
That lent credence to the case that as the economy slows, this will diminish demand for goods, damping price increases.
