MELBOURNE (Reuters) - Pilbara Minerals Ltd on Tuesday took a stake in its Australian lithium mine off the market, cut its sales forecast and curbed spending plans amid a downturn in the market for the battery raw material.The Western Australian miner had been looking for a partner to help it fund an expansion of its Pilgangoora lithium project in the northwestern Pilbara region in Western Australia in return for a 20%-49% stake in the mine. "The Pilbara Minerals Board does not believe the..