By Nicole Maestri

NEW YORK (Reuters) - Macy's Inc (M.N: Quote, Profile, Research) reported a quarterly loss on Wednesday, hurt by restructuring costs and falling sales, but the department store operator stood by its full-year earnings forecast and its shares rose as much as 8 percent.

"Given the very difficult economic environment, our company performed relatively well compared to the competition in the first quarter," Chairman Terry Lundgren said in a statement.

He added, "Earnings per share are on track to deliver the annual guidance provided at the outset of the year."

But Macy's, whose shares had fallen 7 percent this year through Tuesday, expects the U.S. economic environment to remain challenging at least through the third quarter. It said it would need an earlier and stronger recovery to hit the high end of its full-year same-store sales forecast.

"We do not know when the environment will improve and, therefore, the key will be maintaining flexibility," Chief Financial Officer Karen Hoguet said on a conference call.

"Our merchants must ... be conservative in placing inventory orders, and we also have to have contingency plans in place to be ready to reduce expense and capex further should our sales trends not start to improve."

Macy's, which operates its namesake and Bloomingdale's chains, said it lost $59 million, or 14 cents a share, in its fiscal first quarter, ended May 3, compared with a profit of $36 million, or 8 cents a share, a year earlier.

Excluding restructuring costs of 13 cents per share and a reserve of 3 cents per share for a potential litigation settlement, Macy's earned 2 cents per share from continuing operations. On that basis, analysts' average forecast was a loss of 2 cents per share, according to Reuters Estimates.