Manufacturing activity in the Philadelphia area continues to expand in January with all broad indicators remaining positive and supported by a pickup in new orders and employment, the Philadelphia Fed's survey showed on Thursday.

But the index of current activity edged slightly down to 19.3 in January from a revised reading of 20.8 in December, according to the survey which assesses the economic health of the manufacturing sector in Philadelphia district.

The survey's results suggest that increases in input prices continue to be widespread this month, and that more firms reported increases in prices for their manufactured goods. The firms expect a continued expansion in business activity over the next six months, according to the survey's indicators of future activity the Fed said in a statement.

Fifty-four percent of the firms reported higher prices for inputs, compared with 52 percent in the previous month. On balance, firms also reported a rise in prices for their own manufactured goods.