Former General Electric Co. Chief Executive Officer Jack Welch, hospitalized since July for a spinal infection called discitis, is improving and expects to be released in three to four weeks, his wife said in a telephone interview.

“Jack’s doing a lot better,” Suzy Welch said, adding that Welch walked 10 city blocks yesterday outside New York-Presbyterian Hospital, where he’s receiving treatment. “He steadily continues to improve. Certainly three to four weeks feels extremely doable.”