Transport operator SMRT Corporation posted a 20.1 per cent rise in full-year earnings to $109.3 million - the first time in four years the group has crossed the $100 million profit mark.

The creditable performance came on the back of a 6.2 per cent rise in revenue to $1.37 billion for the 12 months to March 31, and a 5.4 per cent increase in operating expenses to $1.24 billion.

The biggest increase in percentage terms was in staff costs, which climbed 10.8 per cent to $536 million, while the biggest cost reduction was in power and fuel, which shrank by 12.2 per cent to $132.3 million.

Fourth-quarter net profit rose by 27.6 per cent to $26.6 million, while revenue was up 2.8 per cent at $320 million.

Earnings per share for the year was at 7.17 cents, up from 5.98 cents previously, while operating margins before interest, tax and depreciation improved to 26.4 per cent, from 25.4 per cent previously.

Net asset value per share was 60.10 cents as of March 31, up from 56.47 cents a year earlier.

At the operating level, the Temasek Holdings-owned firm's rail business posted a profit of $7.4 million, 22.5 per cent lower than last year. Once the star performer, this segment was dragged down by higher investments needed to improve reliability as well as heavier bleeding from its LRT division.

SMRT had a property tax refund of $17.1 million because of previous over-assessments. If not for this refund, the rail segment would have gone into the red, it said.

Its bus business made a profit of $5.9 million, up from a loss of $6.5 million last year, while the taxi division posted a 24 per cent rise in operating earnings to $17 million. Its engineering division narrowed its losses to $29,000, from $2.4 million.

The non-transport businesses continued to glow. Rental income grew 4.7 per cent to $83.4 million - about 11 times what its trains made.

Advertising operating profit grew 3.8 per cent to $22.7 million.

SMRT recognised an impairment for receivables of $2.65 million, up from $1.1 million in the previous year. Its total borrowings remained flat at $821.2 million, and it was in a net current liabilities position of $296.4 million.

Cash and equivalents stood at $232.2 million, up from $156.1 million. Group gearing lowered to 0.64, from 0.77.

A final dividend of 2.5 cents per share was declared, up from 1.75 cents last year.

SMRT chief executive officer Desmond Kuek said: "The group's overall earnings have been supported by better performance in our non-rail businesses, and we will continue to pursue sustainable growth in line with our core competencies as a multi-modal transportation group."