SHARES closed higher yesterday but analysts said gains were limited by uncertainty over the deepening budget crisis in the United States. The blue-chip Financial Times Stock Exchange 100-share index closed at 3,547.9, up 11.1 points from the previous close. The narrower FT-30 index closed at 2,604.4, up 15.9. Analysts said US sentiment had been severely dented by the country's budget impasse, and the nervousness had raced across the Atlantic to infect investors in London. But investors were still able to take limited advantage of a basically strong market and reported a modest gain at the close, they said. Engineering group Rolls-Royce surged 12.5 pence to 173.5 pence after winning a major order for aeroplane engines from Singapore Airlines. British Gas was up five pence to 243.5 pence ahead of the release of its quarterly profits today. Industrial gases group BOC Group rose 10 pence to 874 pence after reporting a 59 per cent rise in profits. A profits warning from paper manufacturer Arjo Wiggins saw its shares drop 14 pence to 192 pence.