WASHINGTON—Wall Street companies didn’t borrow from the Federal Reserve’s emergency lending program over the past week while commercial banks scaled back, sending a sign of some improvements in credit strains.

Investment firms did not draw loans for the week ending July 9. They borrowed just $1.7 billion in the previous week, down from 6.1 billion in the week before that. Such borrowing rose as high as $38.1 billion in early April.

The investment houses were given similar loan privileges as commercial banks in March after a run on Bear Stearns pushed the nation’s fifth-largest investment bank to the brink of bankruptcy and raised fears that other Wall Street firms might be in jeopardy. The company was taken over by JPMorgan.

Banks, meanwhile, averaged $12.9 billion in daily borrowing for the week. That compared with $14.9 billion in the previous week.

The identities of commercial banks and investment houses are not released.

In the broadest use of the central bank’s lending power since the 1930s, the Fed in March scrambled to avert a market meltdown by giving investment houses a place to go for emergency overnight loans. The program will continue for at least six months. Commercial banks and investment companies now pay 2.25 percent in interest for the loans.