TORONTO — In the province of Ontario it was once common to see downtown streets lined with production trailers. But the weak U.S. dollar and increasingly competitive tax breaks from U.S. states are making it tough to attract Hollywood.In January, the provincial government responded to a downturn in nondomestic film shoots by boosting tax credits for foreign projects to 25% of labor spend, up from 18% last year when the program delivered C$37 million ($36.2 million) in tax credits. “The government is very supportive of the film and TV industry and recognizes an increase was necessary to continue in a very competitive environment,” says Donna Zuchlinski, manager of film at the Ontario Media Development Corp. Tax breaks have played a vital role in convincing American productions to shoot here, she adds. Other Canadian provinces have also amped up their incentives to help counter the exchange rate. Lionsgate’s “Saw” franchise is now filming its fifth installment in Ontario. The films, which each cost about $10 million to produce, moved from Los Angeles to Toronto after the first pic. Zuchlinski credits the series’ migration to co-producer Daniel J. Heffner’s strong relationship with the local film industry. “That’s what brings clients back — the comfort level of having everything they need,” she says. “Saw V” is among several pics Lionsgate is now shooting in Canada, says Peter Wilkes, the studio’s senior VP of investor relations. “(The province) remains very friendly to motion pictures and television production and provides us with a cost-effective location to shoot,” he notes.