ATHENS (Bloomberg) — Bermuda-based Tsakos Energy Navigation announced a doubling of third-quarter profit and said full-year earnings will rise to a record after the company expanded its oil-tanker fleet and increased charges to customers.Net income rose to $44.5 million, or $2.33 a share, from $19.2 million, or 98 cents, a year earlier, Athens-based Tsakos Navigation said in a statement late yesterday. Sales, excluding commissions and voyage costs, rose 88 percent to $93.5 million, after the fleet expanded to about 37, from 26 a year earlier.

“Our aggressive expansion program continues to be very rewarding,” President Nikolas P. Tsakos said in the statement. “We will add an additional 15 new buildings to our fleet between 2007 and 2009.”

The decline in shipping rates in the third quarter was “shorter and milder” than usual, the company said. Tsakos Navigation hired its vessels for a daily average of $29,779, 28 percent more than a year earlier.

Tsakos Navigation has one of the world’s largest fleets of ice-class tankers and its first liquefied natural-gas ship is due to be delivered in January. The company plans to charter the ship for three to five years, Tsakos said.

“We believe the market to 2010 is going to be very well balanced and spot rates are still accretive and healthy,” Tsakos told analysts during a conference call.

There is “significant appetite” for ships that can move through icy waters, or so-called ice-class ships, and “lots of interest” for vessels that can carry LNG, he said.

Tsakos Navigation also benefited in the quarter from a $13.3 million one-time gain related to the sale of its two remaining single-hull tankers. There will be a gain of $50 million in the fourth quarter from ship sales.

The company has hired out 93 percent of its ships’ availability in the fourth quarter and the remaining time should be sold at “healthy” rates, the company said.

The contracts should generate $85 million in sales, a presentation posted today on the company’s website showed.

The ship company also has hired out 80 percent of its ships’ availability in 2007, which will produce $250 million in revenue. So far, 70 percent of the fleet is rented in 2008, generating $220 million, according to the presentation.

Tsakos Navigation has 37 vessels, with a further 15 on order. The company reported full-year profit of $161.8 million for 2005.

Shares of the company rose 64 cents, or 1.5 percent, to $44.80 at 12:40 p.m. in New York, giving it a market value of $853 million. The stock has risen 22 percent this year, outperforming the 8.8 percent gain in the six-member Bloomberg Tanker Index.