An array of federal and state investigations into the way banks foreclose on delinquent homeowners has contributed to a sharp slowdown in foreclosures nationally, especially in hard-hit cities like Phoenix, according to a front-page article by David Streitfeld in yesterday's edition of The New York Times.

The article said that over the last several months, some banks have been reluctant to seize homes from distressed borrowers, economists and government officials say, as they fact scrutiny from regulators and the prospect of sanctions when investigations wrap up in the coming weeks and months.

In its most recent housing report, the Obama administration said that foreclosure activity fell 21 percent from October to November, the biggest monthly decline in five years, according to the article.

The pace of foreclosures, furthermore, could be curtailed by court action. The highest court in Massachusetts invalidated two foreclosures Friday in that state, ruling that U. S. Bancorp and Wells Fargo failed to prove they owned the mortgages when they foreclosed on homes.

Fewer foreclosures means that buyers pay more for the ones that do come to market, which strengthens overall home prices and buildings consumer confidence in housing, the article said.

The drop in foreclosures began in September when some lenders were revealed to have been used so-called robo-signers to process thousands of foreclosures without verifying the accuracy of the data. Although the banks have repeatedly said their procedures are sound, preliminary results of several of the investigations have indicated substantial problems.

The diminished supply of foreclosed homes has already had an effect on prices at the auctions in Phoenix where values have fallen more than 50 percent since 2006, bidders said.