The world's biggest economy barely grew in the first quarter as worse-than-expected data revealed the impact of weather disruption in the period.
The US dollar weakened as a result to leave sterling at near to 1.69 against the greenback, with the pound also benefiting from yesterday's 0.8% rise in UK GDP. It was flat against the resurgent euro, at 1.21.
The FTSE 100 Index maintained its position at an eight-week high despite the US figures, with the top flight ending the session up 10.1 points at 6780.
Royal Dutch Shell had a major bearing on the performance after new chief executive Ben van Beurden's first results update triggered a 4% jump in the oil giant's share price to 2520p after better underlying performance.
Elsewhere in the sector, Heritage Oil was 23% higher after the Jersey-based exploration and production company accepted a bid from a Qatari firm that values it at 320p per share, a 25% premium to yesterday's closing price.
Shares topped the FTSE 250 Index risers board, up 59.6p at 315.2p.
Back in the top flight, Rolls Royce surged 3% after it confirmed talks with Siemens over the potential sale of its gas turbine and compressor business.
Siemens is also interested in the energy business of Alstom as it looks to derail an existing deal between the French firm and US giant General Electric.
Rolls shares rose 29p to 1050p as analysts welcomed the moves to raise funds from the disposal of a business that has lacked scale.
GlaxoSmithKline fell 2% to 1632p after Britain's biggest drugmaker reported a 10% drop in sales to £5.61 billion in the first quarter.
Meanwhile Home Retail Group, which Homebase and Argus, said its turnaround plan had seen its underlying profits improve 27% to £115.4 million - the first rise in six years - although the figure was lower when including one-off items.
Shares fell 2p, or 1%, to 204p.
Mike McCudden, head of derivatives at Interactive Investor, said: "With a largely upbeat earnings season, combined with M&A activity driving capital inflows, there is a real chance markets can keep the momentum going and break higher."
The biggest FTSE 100 risers were Barratt Developments up 18.2p at 369.5p, Royal Dutch Shell ahead 89p at 2520p, Shire up 115p at 3378p and WPP ahead 38p at 1274p.
The biggest fallers were Tesco down 10.35p at 292.95p, Admiral off 44p at 1398p, GlaxoSmithKline down 33.5p at 1632p andBritish American Tobacco off 70p at 3417p.