(Adds details from letter and background on fund)
April 20 (Reuters) - Hedge fund manager David Einhorn's Greenlight Capital has taken a new stake in General Motors Co , nearly a year after selling off it position in the automaker, the firm said in a letter to clients on Monday seen by Reuters.
The $11 billion fund believes General Motors has put behind it the impact of recalling more than 2.5 million vehicles in 2014 because of ignition switch problems. It expects GM to begin its $5 billion share buyback soon.
Greenlight has been closely watched by investors ever since Einhorn bet against Lehman Brothers months before the investment bank crumbled in 2008.
Einhorn acknowledged this year has been difficult for the fund as it lost 1.7 percent in the first three months of the year, hurt by a 23 percent drop in Micron Technology Inc. The broader stock market was barely in the black.
"The portfolio had an uneventful and unprofitable quarter," the firm said in its letter dated April 20. "Though the broad market did little, we did even less."
The fund added two new position in stocks that had been beaten down, aircraft leasing company AerCap Holdings NV and engineering and construction company Chicago Bridge and Iron Co NV in the first quarter.
Greenlight said it sold its position in Aetna Inc. It also exited three "losing short positions that fell victim to takeovers." These were Safeway Ltd, Freescale Semiconductor Ltd and Lorillard Inc.
It noted it is tougher to find good long positions because company valuations are on the high side and earnings are in a "precarious spot." (Reporting by Narottam Medhora in Bengaluru and Svea Herbst-Bayliss in Boston. Editing by Alan Crosby and Andre Grenon)