The number of people under 30 who committed suicide last year over job-hunting futility hit 150 as the employment rate for college graduates sank to a record-low 91 percent, and the jobless rate for youths was nearly double the national average, the National Police Agency said Sunday.

The suicides were around 2.5 times worse than in 2007, when the NPA began tracking such data, but down slightly from 159 in 2010, it said.

"It is difficult to take sufficient measures to prevent suicides caused by job-hunting failures, because these are brought about by economic factors, such as a deterioration in the job market and an increase in nonregular employment," a Cabinet Office official in charge of suicide countermeasures said.

Employment conditions for young adults have been bleak since companies started curbing hiring when the collapse of Lehman Brothers Holdings Inc. ushered in a global financial crisis in 2008. This was worsened by the March 2011 quake, tsunami and nuclear disasters and the yen's appreciation.

The average jobless rate for people between 15 and 24 stood at 8.2 percent in 2011, nearly double the national average of 4.5 percent.

With job hunting by university students in full swing since April, the government has been trying to lend a hand while reviewing suicide countermeasures for the first time in five years, government officials said.

The NPA compiled the data by examining suicide notes and interviewing the kin of the deceased.

The total consisted of 52 students, including 41 who were in university, and four high school students; 126 of the 150 were male.

The number of suicides stood at 60 in 2007 but shot to 91 in 2008, before surging to 130 in 2009, according to the NPA.