SINGAPORE - Earnings for engineering firm Tritech Group shot up sharply in the second quarter, though most of that did not come from the company's core business.

Turnover climbed 17.7 per cent from last year to $15.7 million, though higher costs of sales resulted in a slight 2.1 per cent drop in gross profit, the company said on Thursday.

However, the Catalist-listed company's other income shot up 272.6 per cent to $8.9 million from the preceding year.

As a result, net profit jumped to $2.8 million for the three months to Sept 30, up steeply from the mere $18,000 it recorded the previous year.

Tritech said in a Singapore Exchange filing that its engineering business was bringing in thinner gross profit margins.

The jump in its other income was mainly due to an one-off gain of $8.8 million, which it got by converting convertible bonds to shares of its unit Terratech.

This was upon the listing of Terratech on July 30 this year. Terratech produces marble from Malaysia.

Tritech shares were up 0.2 cents to 14.9 cents at around 12.30pm on Thursday.