Recording its first audience figures since relaunching as a UK-wide network in the New Year, Kiss attracted 4.07m listeners in the three months to March 27, up 20% year-on-year, according to the latest RAJAR data.
The Kiss brand registered a 2% total audience share, while nationwide breakfast show Rickie, Melvin & Charlie in the Morning increased its reach by 16% year-on-year.
Bauer, which recently reorganised its radio stations into two portfolios, increased its overall reach to 13.4m listeners in the quarter from 12.3m in Q1 2010.
Steve Parkinson, managing director of Bauer Radio London, said: "We couldn't be happier with the results for Kiss since taking the brand to a national level earlier this year.
"We have seen increases in all four corners of the Kiss world over the past year - nationally, in London and in the East and West of England."
However, Kiss was only the fourth most popular station in London, despite pulling in 1.82m weekly listeners in the quarter, up 9.2% year-on-year and representing a 4.7% share of the London audience.
Capital regained the London crown after attracting 2.18m listeners a week, with a 6.1% share of the audience. Fellow Global station Heart came in second with a weekly reach of 2.11m listeners, ahead of Magic's 1.99m. However, Magic's audience share of 5.3% actually put it ahead of Heart's 4.9%.
Johnny Vaughan and Lisa Snowdon's breakfast show on Capital was the top London commercial breakfast programme, attracting 1.23m listeners between 6am and 10am.
The duo were ahead of Jamie Theakston and Harriet Scott on Heart, who had 860,000 listeners, and Neil Fox on Bauer's Magic 105.4, who had 839,000 listeners.
Smooth Radio London had 643,000 listeners in the quarter, up 37.7% on Q4 2010 and commanding a 1.8% share of the audience. Global Radio's Xfm was up 16.6% year-on-year to 604,000, with a 1.3% share. BBC London 94.9, the BBC's station in the capital, was up 6.9% year-on-year to 557,000, with a 1.7% share.
The Capital brand also went nationwide in the first quarter of 2011, attracting a weekly audience of 6.71m, marginally down on the previous total of 6.76m when its constituent stations had separate identities. The Capital network had an audience share of 4.2%.
Absolute Radio had a weekly reach of 1.39m listeners in the quarter, up slightly on its all-time low of 1.37m in the final three months of 2010. The station had a 1% audience share.