Liberty Media has expressed concerns about crashing viewing figures that commercial boss Sean Bratches says is due to the trend for pay TV deals.

The Daily Mail says the limited coverage in Britain provided by free to air broadcaster Channel 4 is down a whopping 4.3 million over the first five races of 2019.

In Britain, pay broadcaster Sky has exclusive live rights for practice, qualifying and the races.

"It concerns us in a pretty material way, not just for Britain but around the world," Bratches admitted.

"From a brand standpoint, Formula 1 is nowhere near the position where it can lose free-to-air viewership. This is an agreement that was done prior to our arrival," he said, referring to deals put in place by Bernie Ecclestone.

"The pay element is very exciting revenue-wise but from a reach standpoint it is sub-optimal."

But Bratches said he contractually cannot do anything about the situation unless Sky was to "initiate" a change.