The Australian advertising market fell 11.6% year on year to AU$634 million in April based on Standard Media Index data, compared with the same period last year, which was boosted by federal election spending, Jefferies said in a Monday note.

The market decline was 5.5% year on year, excluding the impact of the federal election.

Outdoor advertising proved to be the "most defensive" ad category, with underlying figures up 0.8% year on year, as billboard and street furniture segments grow.

The positive outdoor trend should alleviate concerns about the outlook for Nine Entertainment Co.'s (ASX:NEC) recently acquired billboard business, QMS, which is expected to hit double-digit growth in the fourth quarter of the year, Jefferies said.

Additionally, reports suggested Foxtel may partner with Seven or Ten to bid for the National Rugby League broadcasting rights, but Jefferies believes it is unlikely, with Seven broadcasting the Australian Football League and Ten facing financial pressure.

Jefferies has a buy rating on Nine Entertainment with a AU$0.96 price target, while it has a buy rating and a AU$1.35 price target for outdoor advertising firm oOh!media (ASX:OML).