Among the companies whose shares are expected to actively trade in Monday's session are BP PLC (BP), Aon Corp. (AON) and Hewitt Associates Inc. (HEW). Shares of BP PLC gained amid media speculation that the whole firm or some of its assets may be sold off. The Wall Street Journal reported that BP was in talks to sell assets to Houston-based Apache Corp. (APA) in a deal that could be worth as much as $10 billion. The Sunday Times said Exxon Mobil Corp. (XOM) and another U.S. oil firm have asked the U.S. government whether they could bid for BP. Meanwhile engineers have made "significant progress" in efforts to replace a cap over a gushing oil well in the Gulf of Mexico, Coast Guard Commander Thad Allen said Monday. BP rose 3% premarket to $35.07. Insurance broker Aon has agreed to buy human-resource consulting and outsourcing company Hewitt Associates in a cash-and-stock deal valued at about $4.9 billion. The deal will nearly triple the size of the Aon's consulting operations, making it a $4.3 billion business by revenue. Aon Hewitt, as the consulting and outsourcing operations will be known, will be run by Hewitt Chairman and Chief Executive Russ Fradin. Aon fell 10% to $34.50 premarket, as Hewitt jumped 31% to $46.50. Retailer Tuesday Morning Corp. (TUES) reported fourth-quarter sales that came in ahead of analysts' expectations, and projected fourth-quarter earnings also above the consensus view. The company is expected to fully release the fourth-quarter results on August 24. Shares rose 10% to $4.75 premarket. Needham & Co. raised its stock-investment rating on educational products company LeapFrog Enterprises Inc. (LF) to strong buy, as the analysts said their retail checks indicate the company's products enjoyed very strong sales in the second quarter, and the second half outlook remains promising. Shares rose 7.4% to $4.65 premarket. Watch List: Bristol-Myers Squibb Co. (BMY) and Otsuka Pharmaceutical Co. said the Food and Drug Administration has agreed to give a priority review to cancer drug Sprycel as a first-line treatment of adults with newly diagnosed chronic myeloid leukemia in chronic phase. The FDA is expected to rule on the new use for the drug by Oct. 28. Sprycel already has FDA approval for patients who fail to improve after taking Novartis AG's (NVS, NOVN.VX) Gleevec. Standard & Poor's Ratings Services raised Domtar Corp. (UFS, UFS.T) out of junk territory, citing its improved operating performance and deleveraging. Moody's Investors Service recently raised its rating on the Canadian paper maker to the top level before investment grade, citing the same factors. Standard & Poor's Ratings Services downgraded its junk ratings on iStar Financial Inc. (SFI) to highly speculative territory, citing the finance company's limited funding flexibility and severe deterioration in the credit quality of its loan portfolio. Shares fell 1.4% to $4.25 in after-hours trading. Lions Gate Entertainment Corp. (LGF) confirmed Friday that it and activist investor Carl Icahn will jointly set aside their differences and work on a possible unspecified acquisition for 10 days. The film and television studio and Icahn have been locked in a tense control battle for months. NYSE Amex, a unit of NYSE Euronext (NYX), said it will begin trading Nasdaq-listed issues Tuesday assuming approval by the Securities and Exchange Commission. -By Dow Jones Newswires; write to [email protected] (END) Dow Jones Newswires July 12, 2010 08:27 ET (12:27 GMT)