The Milton Keynes-based agency's pre-tax profits fell from £509,070 to £28,049 in the year to June 2009, and will record its latest annual accounts with Companies House at the end of this month.
In the first six months of BI's 2010/2011 financial year, which runs from 1 July to 30 June, turnover has risen 15 per cent, according to managing director Mike Davies.
Increased activity from Chevrolet, Lexus and Toyota have boosted BI's fortunes. The agency is also producing a 300-delegate conference on 23-25 March for Nissan's dealers.
"After two very difficult years, it is very pleasing to see the changes that we've made to our business produce such positive results," said Davies. "This is testament to the commitment and hard work of our associates."