Insurance companies are deterring women by spending millions of pounds on sports sponsorship aimed mainly at men, according to Datamonitor.
Datamonitor said the sponsorship of football, rugby and motor racing was just one example of ineffective marketing by financial services.
"Their sponsorship is targeting largely male audiences and missing a really big opportunity to target female audiences," said Stephanie Wyman, author of the report.
The largest sponsors are insurer Axa, which spent £27 million on football's FA Cup, Nationwide, which spent £25m on football, and HSBC, with £25m on motor racing, according to the report.
But Axa spokesman David Ross said its own market research proved the sponsorship of the FA Cup was a success.