Spending on new businesses has caused a five per cent fall in half year profit for the owner of Radio Rentals, Thorn Group.

Thorn’s profit of $13.3 million for the six months to September 30, is down from $14 million 12 months earlier.

The company spent $300,000 starting up its new car rental business, while in the previous corresponding period it made $1.25 million on the sale of debt.

Radio Rentals’ revenue grew, but earnings dropped because of spending on new stores, Thorn said.

The company also operates a financial services business, provides equipment financing and offers credit.

It said its strategy to diversify its business was expected to deliver growing returns in the medium term, but full year profit growth will be limited by spending on new businesses.

Thorn Group shares were down nine cents, or 3.6 per cent, at $2.40 at 1343 AEDT.