Recent turmoil in financial markets had a noticeable effect on the ailing housing sector but its impact on the rest of the U.S. economy so far seemed limited, the Federal Reserve said Wednesday in a nationwide survey.

In most parts of the country, "the recent developments in financial markets has led to tighter lending standards for residential mortgages, which was having a noticeable effect on housing activity," said the survey, or Beige Book.

Several districts noted that the reduction in credit availability added to uncertainty about when the housing market might turn around, it added.

The survey on economic situation is based on information supplied by the Fed's 12 regional banks and collected before August 27.

While several districts noted that commercial real estate markets had also experienced somewhat tighter credit conditions, a number commented that credit availability and credit quality remained good for most consumer and business borrowers, according to the survey.

"Outside of real estate, reports that the turmoil in financial markets had affected economic activity during the survey period were limited," the survey said.

It said that reports from the Fed districts indicated that "economic activity has continued to expand" at a moderate pace.

According to the survey, retail sales were generally positive, with increases characterized as modest to moderate.

Manufacturing activity expanded across most districts, with reports of softening demand for building materials and autos.

Nearly every district reported at least modest increases in employment during the recent survey period. And most districts reported little change in overall price pressures.

The U.S. central bank releases the Beige Book eight times a year. Information from the survey will figure into discussions at the Fed's next policy-making meeting to be held on Sept. 18.