"I have decided to return capital to investors at the end of the third quarter," Karsch wrote to investors on Wednesday, according to a letter seen by Reuters.

Karsch, whose biggest investments include Yahoo Inc (>> Yahoo! Inc.) and Expedia (>> Expedia Inc), said that 95 percent of the fund's $1.8 billion in assets would be returned to investors by the end of next month while the last 5 percent would be returned in January after the fund's audit.

Looking back over his fund's run, the 45-year-old manager said "it is time for me to take a step back, reflect on my experiences and begin to think about the next chapter of my career."

Karsch Capital's main fund was up 6.1 percent this year through the middle of August. In the letter, Karsch said that over the life of the fund it outperformed the Standard & Poor's 500 index by approximately 100 percentage points with one-third of the volatility.

While Karsch, who previously worked at Soros Fund Management, did not tip his hand as to what he may do next, he said that he is "very excited about the opportunities that lie ahead."

A spokesman declined to comment.

News of Karsch's decision comes almost exactly three years after Stanley Druckenmiller, who established his reputation as one of the industry's best managers for betting against the British pound while he worked at Soros Fund Management, announced his retirement at age 57. Since then a number of other managers, including Chris Shumway, have also shut down their firms.

(Reporting by Svea Herbst-Bayliss; Editing by Phil Berlowitz)

By Svea Herbst-Bayliss

Stocks treated in this article : Yahoo! Inc., Expedia Inc