BOSTON ( TheStreet) -- Sara Lee ( SLE) was one of several stocks poised to move on above-average volume Monday after the food and beverage company rejected a $12 billion leveraged buyout, according to a report.Sara Lee rejected an unsolicited proposal from private-equity company Kohlberg Kravis Roberts ( KKR) several weeks ago, a person familiar with the matter told The New York Post. Sara Lee is now conducting a search to permanently replace former CEO Brenda Barnes and sell its bakery business for approximately $1 billion, the source said. Barnes stepped down from the CEO position on Aug. 9 due to health problems. Shares of Sara Lee are jumping by $2.22, or 16.5%, to $15.65 in the premarket session. The average daily share volume for Sara Lee is 8 million. Elsewhere, Dynamex ( DDMX) shares are rallying by $5.78, or 37.8%, to $21.09 in the premarket session after Greenbriar Equity Group said Friday it will take the same-day delivery company private in a $210 million deal. Dynamex shareholders will receive $21.25 per share in cash. The average daily share volume for Dynamex is 31,000. Actel ( ACTL) shares are climbing by $4.80, or 30%, to $20.82 in the premarket session after Microsemi ( MSCC) said it will buy the field-programmable gate arrays company for $430 million, or $20.88 per share. The average daily share volume for Actel is 79,000. Array BioPharma ( ARRY) shares are up 31 cents, or 10%, to $3.42 in the premarket session after the company late Friday announced positive interim results of its oral HER2 (ErbB2) inhibitor, ARRY-380, in a Phase 1 trial in patients with advanced breast cancer. The average daily share volume for Array BioPharma is 187,000. On the downside, shares of GTSI Corp. ( GTSI) are plunging by $3.25, or 44.8%, to $4 in the premarket session after Eyak Technology withdrew its offer to buy the IT solutions company for $7.50 per share in cash. The move comes after the U.S. Small Business Administration suspended GTSI from receiving any future contract awards from the federal government. The average daily share volume for GTSI is 32,000. -- Written by Robert Holmes in Boston. >To contact the writer of this article, click here: Robert Holmes. >To follow Robert Holmes on Twitter, go to http://twitter.com/RobTheStreet. >To submit a news tip, send an email to: email@example.com.