Earnings before interest and tax (EBIT) at the Oslo-listed group almost doubled to $118 million in April-June from $62 million a year earlier, beating an average forecast of $96 million in a Reuters poll of 13 analysts.
"Based on the current weakness in the tanker market and the company's trading results achieved so far...the board expects a materially lower result in the third quarter," Bermuda-registered Frontline said in a statement.
The firm said it would pay a dividend of $0.75 per share for the quarter, up from $0.25 a year earlier and beating the average forecast of $0.72 per share.
Frontline, controlled by Norwegian shipping tycoon John Fredriksen, said it was somewhat concerned about the high number of expected vessel deliveries which will come to the market in the next two years and the effect the net fleet growth will have on the market balance.
"However, the actual deliveries in 2009 and in the first half of 2010 have been significantly lower than anticipated and this development is likely to be further strengthened by the expected delays, slippage and cancellations of new building orders," Frontline said.
Frontline said this month that it had put some of its vessels at anchorage due to sliding freight rates under pressure from a build up-of ships.