Database conglomerate InfoUSA, Omaha, NE, is not in negotiations to purchase the R.L. Polk Co., InfoUSA chairman/CEO Vinod Gupta told DM News yesterday, but sources said he had been in discussions to acquire the Southfield, MI, data concern until recently. Polk's asking price might have been too high, the sources indicated. A spokesman for Polk declined to comment, and Gupta declined to discuss the matter further. Rumors have been circulating for years about the possible acquisition of all or part of Polk, a privately owned company that had revenues of $415 million in the fiscal year that ended last March. The company compiles automotive data and supplies products it services for the transportation industry. It also provides direct marketing services and database management and compiles lifestyle and demographic data.