Washington (CNN) -- Energy Secretary Steven Chu will resign from President Barack Obama's Cabinet in coming weeks, he told Energy Department staff in a letter on Friday. Chu, who turns 65 this month, was a leading advocate in the Obama administration for alternative energy development, making him a target of the fossil fuel industry and its conservative supporters in Congress. He was a co-recipient of the Nobel Prize for Physics in 1997 and headed the Department of Energy's Lawrence Berkeley National Lab and taught at the University of California before becoming energy secretary in 2009. Read his letter "I informed the president of my decision a few days after the election that Jean and I were eager to return to California," Chu said in the letter. "I would like to return to an academic life of teaching and research, but will still work to advance the missions that we have been working on together for the last four years."
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NEW: Obama lauds Chu for plugging the Gulf oil leak
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Steven Chu says he will stay on until late February or beyond
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Chu is a Nobel Prize winning physicist
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Critics blamed Chu for failed government investments in clean energy development
A statement by Obama thanked Chu for his "dedicated service," saying he "brought to the @placeholder a unique understanding of both the urgent challenge presented by climate change and the tremendous opportunity that clean energy represents for our economy."