Qualcomm (NSDQ: QCOM) has raised its third quarter profit and sales target on greater demand for its mobile phone chips and semiconductors used in 3G networks, but warned that its shipments may decrease in the fourth quarter. The world’s biggest cellphone chip maker said it expected revenue of $2.67 billion to $2.77 billion for the third quarter ending on June 28, up from a previous forecast of $2.4 billion to $2.6 billion. Analysts were forecasting $2.54 billion. Operating income is expected to be in the range of $830 to $880 million, compared to its prior forecast of $550 to $650 million.

Despite the rise in profit and sales targets, not all analysts were convinced that it meant that the cellphone slump was over. Pacific Crest analyst James Faucette told Reuters, “Normally (chip shipments are) up sequentially in the September quarter. Even though they’re raising guidance, which is great, we’re not sure it shows that end demand is getting better.”