President Barack Obama and the other leaders pledged to boost the resources at the IMF and other lending institutions by $1.1 trillion to help developing nations withstand the economic slump. There was little expectation that differences that remain over how to jump-start growth would be resolved during the weekend discussions. The Labor Department also said Thursday that an additional 2.3 million people were receiving benefits under an extended unemployment compensation program enacted by Congress last year, as of April 4, the latest data available. Employers have cut a net total of 5.1 million jobs since the recession began in December 2007. The Labor Department also reported that mass layoffs, or job cuts of 50 or more by a single employer, increased to 2,933 in March, the most on records dating to 1995. More than 299,000 workers were fired in last month's cuts. The manufacturing sector alone accounted for 1,259 mass layoffs, resulting in nearly 156,000 new jobless claims, also records. ____ AP Business Writers Christopher Rugaber and Alan Zibel contributed to this report.