Six years ago, Paric Corp., a $40-million construction company in St. Louis, realized it could no longer rely on prepackaged software to meet its specialized demands. At the same time, it knew that for many companies its size, the cost of customized software could be staggering.

Paul McKee, Paric's chief executive officer, came up with an interesting strategy. He enlisted the aid of contract programmers over a five-year period to set up, and continually refine, a customized software package for such functions as subcontractor bidding and accounting. Last year, when the finished product began to generate interest from local construction companies, Paric set up a new division -- Paric Computer Solutions -- to sell and market the program.

"We had spent so much time and money developing our software, we figured we could offset some of those costs by actually selling it to other companies," says McKee. He expects Paric Computer Solutions, staffed by two salespeople and five programmers, to sell more than $500,000 worth of software in 1985.