Nov. 3 (Bloomberg) -- Trading of bullish MEMC Electronic Materials Inc. options jumped to a six-week high on renewed speculation that the maker of silicon wafers for solar modules and semiconductors may be acquired.

Almost 47,800 calls giving the right to buy the stock changed hands, seven times the four week average, as the shares climbed 2.4 percent to $12.60. The most-active contracts were the November $13 calls, which jumped 57 percent to 55 cents and accounted for about a third of today’s call volume. This month’s options expire Nov. 20.

“It’s been a takeover rumor before and it’s definitely a recurring theme,” said Mike Thurow, a senior options strategist at Susquehanna Financial Group LLP in Bala Cynwyd, Pennsylvania. “Typically when you see these kind of rumors people are going to focus on the shorter-term maturities because, if the company is taken over, those are the ones that give the most leverage.”

Today’s volume for the November $13 calls exceeded 14,800 contracts, more than 10 times the open interest, or number of existing contracts, before today. Through yesterday, January $20 calls had the greatest open interest of any option on the stock, at 13,896. Overall open interest for MEMC stands at 113,286 calls to 70,000 puts.

St. Peters, Missouri-based MEMC manufactures silicon wafers for use in semiconductors and solar power panels. Bill Michalek, MEMC’s director of investor relations, didn’t return a phone call seeking comment.

To contact the reporter on this story: Jeff Kearns in New York at jkearns3@bloomberg.net.

Last Updated: November 3, 2009 16:59 EST