Sportscar maker Caterham Cars cut its losses by nearly £15 million last year but bosses said they were “disappointed” with the company’s performance.

The firm, which is co-owned by QPR co-chairman Tony Fernandes, reduced its losses to £5.9 million, compared to £20.4 million in the previous 18 months, when it had a different accounting period.

The Dartford-based company, which makes the distinctive Caterham Seven model, has been forced to cease its expansion plans, put up prices and make redundancies after a tough few years.

The firm suffered heavy losses in 2014 after it mothballed plans to develop a new road car with French manufacturer Renault.

It was forced to write off research and development costs of more than £15.8 million after the failed venture.

Revenues in the year to June 2015 were £19.8 million, compared to £27 million in the previous 18 months, which bosses said gave the firm a 10% year-on-year increase.

It made a gross profit of £4 million, down from £5.9 million, and made an operating loss of £5.6 million, according to its latest accounts filed at Companies House.

This was after deductions for research and development licences, administrative expenses and the write off of £1.2 million of debts owed to it from the administration of its F1 car manufacturing division in 2014.

It has received more than £2 million in cash funding from its parent company Caterham Enterprises Limited.

Bosses said the group, which employs about 130 people, had started the year with “a strong order bank” after the successful launch of new models and an increase in global brand awareness, helped by its racing activities.

An increase in production capacity in the first half of 2015, as it sought to fulfil increased demand, helped its year-on-year turnover growth.

In his financial report, chief executive Graham MacDonald said he was “pleased” to report a return to regular monthly EBITDA profits – earnings before interest, taxes and other charges.

He said the board “are confident that the results for the next financial year will be much improved following all the changes to pricing, improvement to margins and reduction in operating costs”.