Inventories at U.S. businesses held steady in April as sales dipped for a second straight month, the Commerce Department said in a report released on Thursday.

While sales fell 0.5 percent in April to $833.8 billion, inventory levels remained unchanged, at $1.198 trillion, Commerce said. The inventory data was in line with projections of economists polled by Reuters. 

While inventories at the retail level fell, stocks of unsold goods rose at the wholesale and manufacturing levels. The figures may renew worries that firms are continuing to have difficulties working off a backlog of goods, which may hinder new production ahead. 

The stock-to-sales ratio, which measures how long it would take firms to sell down existing inventories, rose to 1.44 months, up from 1.43 months in March. The last time the ratio had been as high was in January 1999, when it was also 1.44 months.