SINGAPORE - The economy grew a "moderate" 2.8 per cent in 2014 as productivity gains remained weak for a third straight year, Prime Minister Lee Hsien Loong said on Wednesday.

But incomes continued to rise, he added in his yearly New Year message.

The growth rate was a tad lower than official forecasts of "around 3 per cent", an outcome that seems to underpin Mr Lee's call to redouble efforts to raise productivity so that salaries and the economy will keep growing.

He also underlined the need for "stability, safety and security" to safeguard Singapore's success and assure its future, as he recalled an "eventful" year marked by, among others, the Ebola outbreak, terrorism and air tragedies, including the latest crash of AirAsia flight QZ8501.

His timely reminder comes as Singapore embarks on its 50th birthday celebrations this year.

"SG50 will be a time to look back, give thanks for what we have achieved, and look forward to the future with confidence."

But crucial to such optimism is higher productivity and, in turn, economic growth.

Productivity, however, has been disappointing, said Mr Lee. It shrank 0.5 per cent in the first three quarters of 2014.

He called for a redoubling of efforts to boost it. "Otherwise, our incomes cannot continue to rise, and will soon stagnate," he said.

The Government will release more economic figures on Friday.

In his message on Wednesday, Mr Lee also wished all Singaporeans a very happy new year.