Cineplex is moving to buy big-screen advertiser Onsite Media Network, looking to add the Alberta-based company to the ad muscle of its Cineplex Media division. The $1.7-million deal would see the cinema chain buy up all issued and outstanding shares of Onsite, which runs ads on screens in office towers and sports centers across Canada. The deal is subject to court, shareholder and regulatory approval. Onsite locations include General Motors Place in Vancouver, the Calgary Saddledome and Toronto’s underground PATH system.