Hedge fund manager David Einhorn told investors on Tuesday that his Greenlight Capital lost money on battered retailer Macy's Inc and exited the position roughly six months after getting in.

"We sold Macy's for a loss after the company announced a significant reduction in full-year 2016 guidance," Einhorn said in a letter seen by Reuters. Macy's and Apple were "material losers" for the firm as it lost 2.6 percent in the second quarter, the letter said.

Greenlight sold Macy's at $32.08 a share after having told investors in January that it had bought the stock at $45.69.