Software maker Verticalnet has agreed to acquire New York consulting firm Tigris for $9.2 million in cash and stock, the companies said on Monday. Verticalnet expects the purchase of Tigris to help it to more than double its revenue this year. Verticalnet, based in Malvern, Penn., reported $9.6 million in revenue last year. Privately held Tigris has 60 employees, and its revenue was roughly equal to Verticalnet's in 2003, a Verticalnet representative said. The deal follows of FreeMarkets, which Ariba expects to complete by June. Both Ariba and Verticalnet compete in the market for business software aimed at streamlining corporate purchasing and contract negotiation.