LONDON (Bloomberg) — National Grid Plc, the UK's power network operator, said first-half profit rose nine percent on improved sales from its US gas distribution unit.

Net income for the six month period ended September 30 climbed to £760 million ($1.2 billion) from £696 million a year earlier, the London-based company said. Sales rose 6.1 percent to £6.4 billion, missing the £6.58 billion estimate of four analysts surveyed by Bloomberg.

Operating profit from gas distribution rose 30 percent to £324 million, National Grid said. Net regulated income rose £24 million, driven by an increase in US revenue on customer growth and rate changes in New York. Warm summer temperatures boosted electricity distribution and generation revenues by about £33 million.