Sterling strengthened Oct. 16 after the U.K. reported stronger-than-expected wage growth data and a still-low unemployment rate.

Average weekly earnings in the U.K., including bonuses, rose 2.7% year over year in nominal terms in the three months to August, following a 2.6% annual increase in the three months to July, the Office for National Statistics said. The Econoday consensus predicted that annual wage growth would remain steady at 2.6%.

The pound was up 0.33% against the U.S. dollar as of 5:01 a.m. ET.

Excluding bonuses, average weekly earnings rose 3.1%, following a 2.9% increase in the three months to July. This was the fastest growth rate since January 2009, Bloomberg News said.

Adjusted for price inflation, earnings grew 0.7% year over year excluding bonuses and by 0.4% including bonuses.

Bank of England Chief Economist Andy Haldane recently signaled that growth in British wages is starting to gain momentum, but said the pace of increase may be gradual.

Meanwhile, the unemployment rate in the three months to August was steady at 4.0%, its lowest level since early 1975, the ONS data said.

"Given that wage growth has been central to the Bank of England's rate hike rationale, this trend is likely to keep them on their tightening track," wrote James Smith, developed markets economist at ING.

"However that is heavily contingent on Brexit, and we think the latest rise in uncertainty could see growth momentum slow once again as we head into the winter."