The Adzuna Job Market Report on online vacancy data is compiled from more than 300 sources. It reveals that advertised starting pay increased by 0.9% across the UK between June 2013 and the same period in 2014. However, the equivalent salaries in London contracted by 1.6%.
Despite this London starting salaries remain significantly higher than the national average – £41,564 compared to £33,873.
The total number of jobs advertised in July was 872,629, up 3.9% from June. Over the same period the number of jobseekers per role fell 6%, from 1.21 to 1.14.
The manufacturing sector saw a large increase (15.9%) in advertised salaries, bringing the average up to £29,507 – the highest since 2012.
The report's author, Becky Harkins, told HR magazine strong hiring in the automotive sector has spurred salary growth in manufacturing.
"We've seen a lot of companies, for example Nissan, creating a lot of jobs in the industry, which is always traditionally strong in this country," she said.
Harkins said London's falling wages are most likely due to jobseekers being constantly attracted to the City's "bright lights".
"Whereas companies elsewhere in the country are seeing a lot more competition for talent, firms in London probably haven't felt that yet," she explained. "It's always going to be a place that attracts people to work, so employers are not having to offer higher salaries to get people through the door."