National Semiconductor Corp has received an upgrade in its credit ratings from Standard & Poor’s Corp, which moved NatSemi’s preferred stock rating to double-B from B-plus to give an implied senior debt rating of doubleB-plus. The rating outlook is stable, the rating agency said, adding that the move reflects the company’s improved product mix over the last few years, its strengthened profitability and cash flows in recent quarters, and its moderate capitalisation. NatSemi is increasing its efforts to serve the communications, personal computing, and analogue-intensive markets where growth is expected to be strong, it said, and has a strong positions in many of these areas, although there is substantial competition, the ratings agency noted.