U.S. economy continued to " expand gradually" in July and early August across most regions and sectors, but the pictures of recovery in retail and manufacturing sectors were mixed, the U.S. Federal Reserve said Wednesday.

In its latest national economic performance survey, the U.S. central bank said that six districts indicated the local economy grew at a modest pace and another three areas cited moderate growth.

Most localities said that retail activity, including auto sales, had increased since the last report, although areas including Cleveland,Chicago, Dallas and San Francisco noted the retail improvements were weak.

The picture in the manufacturing industry was also mixed, as six areas reported that demand for manufactured goods was falling, according to the report.

The survey, known as the Beige Book, was based on economic information supplied by the Fed's 12 regional banks and was released eight times each year to provide a snapshot of the local economy across the States.

Real estate markets were generally said to be improving across the country. On the residential side, all 12 districts cited increases in home sales, home prices or housing construction. Reports on commercial real estate markets were also generally positive, said the Fed.