Sir Frank Williams believes the results show "good progress" © Sutton Images Enlarge

Williams has announced a 25% increase in income in its financial results from 2013.

The group, which includes the Williams F1 team, increased its overall income to £132.4m last year, up from £105.8m in 2012, while its Earnings Before Interest & Tax (EBIT) went from £5.1m to £12.0m. There was also a 26% rise for the F1 team itself, which it put down to a "special non-recurring sponsorship payment" - likely to relate to the sum believed to have been paid by Venezuelan oil company PDVSA for an early termination of its sponsorship deal in order join Pastor Maldonado at Lotus.

The team also had an EBIT of £11.5m, up from 2012's figure of £8.3m. The figures do not take into account the sale of the Williams Hybrid Power and Williams Technology Centre in Qatar in early 2014.

It represents a big tunaround for Williams after losing £5m in 2012. The return to profit coincides with a return to form at the front end of the grid, plus its new deal with title sponsor Martini.

Team boss Sir Frank Williams said the results are positive given the team's on-track struggles last season.

"Although 2013 was a difficult season for the team on the race track, we report these full year results at a time of much optimism for the Williams Group," Williams said. "We have started the 2014 Formula One season well and hope we can continue to improve our performance.

"We made good progress commercially through the winter months and Williams continues to attract an enthusiastic and very loyal group of partners and fans. These annual results demonstrate that we continue to manage our business in a fiscally responsible way and provide the foundation from which we can continue to grow."