Seven West Media has posted a $109 million loss for the half year to the end of December.

The loss was due to $260 million worth of write-downs to the value of the company's magazine business, Yahoo!7 stake (including group buying site Spreets), and redundancy and restructuring costs.

Excluding those one-off costs, the media giant made $142 million in profit.

Seven West's chief executive, Don Voelte, says it will persist in trying to turn-around its Yahoo!7 site, because it is important to the company's future.

"Yahoo7 had a bit of a bump in the road during the half, but we're very confident that they're back on track. They've gone through a transition of management," he said.

"It's extremely important, that they're a long-term part of our vision of where we need to go."

That was not good enough for investors, with Seven West shares falling 7 per cent on the result to $2.34 by 12:18pm (AEDT).