Rising sales of high-speed Internet service helped Hawaiian Telcom earn a $6.7 million profit in the second quarter, the company reported this morning.

It was the second consecutive profitable quarter since the Honolulu-based firm went public in December following an October emergence from bankruptcy.

Hawaiian Telcom’s first-quarter profit totaled $5.5 million. In the second quarter of 2010 during bankruptcy, the company lost $22.3 million.

During the recent second quarter ended June 30, Hawaiian Telcom said it added about 4,500 high-speed Internet subscribers, a 4.6 percent gain over a year earlier. The company also increased packages of bundled residential service by 2,100. The number of land-line telephone customers fell 5.3 percent, though that rate of loss was down from 7.4 percent in the 2010 second quarter. Hawaiian Telcom also launched TV service in the second quarter, but the impact on earnings was not significant.

Total revenue was up 1 percent to $100.7 million in the second quarter from $99.6 million in the same quarter last year.