Since the opening ceremony of the Olympics last week, NBC has been busy negotiating with anxious advertisers, offering ways to make up for the Games’ steep drop in viewers, people familiar with the matter say.

Haggling over "make-goods” isn’t unusual in TV. But the discussions show that NBC’s ambitious Olympics effort from Tokyo is drawing a smaller audience than the broadcaster or advertisers expected. With the coverage at its halfway point, average nightly viewership through Tuesday was down 42% from the 2016 Summer Games across all of NBC’s outlets.

A decline through the second week threatens to eat into the revenue that NBCUniversal counts on to cover expenses and turn a profit from the games. The company, part of Comcast Corp., sold more than $1.25 billion in commercials for this year’s Olympics, a record. It’s paying about $1.1 billion for the broadcast rights.