Premarket roundup: Discount retailers, Tenaris

Among the premarket stories for Friday, May 30, from AP Financial News:

NEW YORK (AP) _ A Piper Jaffray analyst upgraded shares of Big Lots Inc. Friday and downgraded Costco Wholesale Corp., saying both companies will benefit as consumers hunt for bargains, but Big Lots shares have more room for growth.

NEW YORK (AP) _ Higher prices for steel pipe maker Tenaris SA will outweigh growing raw materials costs for the Luxembourg-based company, a Jefferies analyst said late Thursday.

NEW YORK (AP) _ A Lehman Brothers analyst upgraded Nasdaq OMX Group Inc. Friday due in part to recent share declines, but cut his price target on concerns about the broader sector.

NEW YORK (AP) _ Women's apparel retailer Ann Taylor Stores Corp. is better managed now than it was a year ago and stronger profitability is on the way, a Friedman, Billings, Ramsey analyst said Friday.

NEW YORK (AP) _ Two analysts cut their ratings on J. Crew Group Inc. after the apparel retailer lowered its full-year guidance, citing the tepid economic environment.