UPDATE 1-RESEARCH ALERT-Needham downgrades Advent

(Changes source; adds details, stock movement)

Sept 9 (Reuters) - Needham & Co downgraded the stock of Advent Software Inc (ADVS.O) to "buy" from "strong buy," citing the slow pace of client migration to the company's newer technology and fears of a margin slowdown, sending its shares down as much as 11 percent.

"We believe that it has become incrementally more difficult for Advent to migrate clients from its Axys platform to APX and that this is a function of the challenging U.S. economy," Needham said in a note to clients.

Advent's Axys portfolio accounting platform is based on older technology and has less functional capability than APX, but clients choose to delay upgrading, said the brokerage, which cut its price target on the stock by $5 to $60.

Needham was also concerned about challenges in new bookings for the provider of software to investment management firms.

Shares of the company were down $3.76 at $40.57 Tuesday morning on Nasdaq. They touched a low of $39.325 earlier in the session. (Reporting by Kuganandhan Paramanandan in Bangalore; Editing by Amitha Rajan)