By 1940, the average production cost of an American feature was $400,000, a negligible increase over ten years. A number of small Hollywood companies had folded around the turn of the decade, including the ambitious Grand National, but a new firm, Producers Releasing Corporation (PRC), emerged as third in the Poverty Row hierarchy behind Republic and Monogram. The double feature, never universal, was still the prevailing exhibition model: in 1941, 50 percent of theaters were double-billing exclusively, with additional numbers screening under the policy part-time. In the early 1940s, legal pressure forced the studios to replace seasonal block booking with packages generally limited to five pictures (MGM carried on with blocks of twelve for a while). Restrictions were also placed on the majors' ability to enforce blind bidding. These were crucial factors in the progressive shift by most of the Big Five over to A-film production, making the smaller studios even more important as B-movie suppliers. In 1944, for instance, MGM, Paramount, Fox, and Warners released a total of ninety-five features: fourteen had B-level budgets of $200,000 or less; eleven were budgeted between $200,000 and $500,000, a range encompassing programmers as well as straight B movies on the lower end; and seventy were A budgeted at $0.5 million or more. In late 1946, executives at the newly merged Universal-International announced that no U-I feature would run less than seventy minutes; supposedly, all B pictures were to be discontinued, even if they were in the midst of production. The studio did release three more sub-70-minute films: two Cinecolor westerns, "The Michigan Kid" and "The Vigilantes Return", in 1947; the self-explanatory "Arctic Manhunt" in 1949. Fox also phased out B production in 1946, releasing low-budget unit chief Bryan Foy, who had come over from Warners five years before. For its B-picture needs, the studio turned to independent producers like the now-freelance Sol Wurtzel.