USA Networks Inc.'s Home Shopping Network said James Held resigned as chief executive and chairman of the 24-hour cable-television network, less than three months after he was promoted to the chairmanship. Held, who joined HSN as chief executive and president in November 1995, said he is leaving Home Shopping Network because he has accomplished his goals there. Mark Bozek, the network's president, will take on the chief executive's title. It was not clear whether HSN plans to find a replacement for Held as chairman. Held saw HSN through three straight years of revenue and profit growth and has helped to diversify the shopping channel's offerings. The network reaches 70 million homes.