Running a large hospital system has given HCA a lot of experience buying supplies, collecting medical bills and hiring nurses, occupational therapists and others on a contract basis.In a bid to diversify its revenues, the Nashville-based hospital chain now wants to provide such business services to other hospitals ? both for-profit operations and not-for-profits ? through a new subsidiary, Parallon Business Solutions.HCA's rollout of the wholly owned Parallon subsidiary comes as hospitals and health systems appear more willing to use outsourcing to trim operating costs. Pressures are most extreme on not-for-profits because they generally have more difficulty than a public company raising extra capital. "Historically, these not-for-profits would have seen buying from HCA as helping a competitor, but today they're under so much pressure to reduce their costs that that's less of a concern," said stock analyst A.J. Rice of Susquehanna Financial Group in New York.