'diminish in value' is correct and usable in written English.
You can use it to describe a situation in which the value of something decreases. For example, "The value of the company's stock has diminished in value significantly over the past year."
Talent increases in an individual through experience and the application of education, whereas commodities diminish in value over time: coffee, once drunk, is spent.
The comparison to a house is not a valid one: a house is an asset you can sell again, whereas the sofa or television is something that will diminish in value to the point of worthlessness.
Time Warner said that Cablevision "has demanded unprecedented rates for programming that continues to diminish in value," referring to the loss of the Yankees and the Nets to YES, and had refused to sign an extension allowing Time Warner to carry the channels while negotiations continued on a long-term deal.
Otherwise, content for content's sake will diminish in value and begin to work against your company.
Whether or not it's preferable to voucherize it with coupons that diminish in value is debatable as an optimal solution.
His plan to reduce long-term health care costs is to ration out vouchers that diminish in value over time, relative to rising costs.
As Kraft shares dipped, its offer was diminishing in value.
The others have diminished in value by an aggregate $60 billion.
Still, he now knows one prior asset has diminished in value.
For the library, those damages would involve factoring in how much the Donnell site had diminished in value since Orient-Express agreed to buy it in November 2007.
RICHARD WILLIAMS: I can't help feeling that Roger Federer's wins in 2009, marvelous though they were, were slightly diminished in value by the problems Nadal suffered.
