Churchill Downs Inc. and the Stronach Group have renewed a partnership agreement that will keep the horse race broadcasting network HRTV on the air until 2015, the two companies said on Wednesday.The renewal includes commitments by both companies to supply the signals from their tracks exclusively to HRTV, which is available on Dish Network and several local cable networks. The tracks include Churchill Downs, Arlington Park, Fair Grounds, Calder Race Course, Gulfstream Park, Santa Anita Park, Laurel Park, and Pimlico Race Course.HRTV is a competitor of Television Games Network, the horse racing channel that is available on DirecTV and some cable networks. TVG, Churchill Downs, and the Stronach Group all own account-wagering companies, and the distribution of racing signals through the networks is considered critical to marketing the telephone and Internet betting operations.According to financial statements, Churchill lost $700,000 on its 50 percent stake in HRTV in 2010, a slight improvement on a $900,000 loss in 2009. The two companies formed the partnership in 2007.The Stronach Group is a private company owned by Frank Stronach that was formed on June 30 to take over the racing and gambling assets previously held by MI Developments Corp.