First Horizon National ( FHN) climbed 9.2% to $21.36 on word the Memphis, Tenn., bank will halt lending to national homebuilders and commercial real estate businesses while remaining in the construction-lending industry in its home state and elsewhere in the Southeast. That will hasten the company's intended $2 billion reduction in its national real estate portfolio this year, First Horizon said. Also riding higher was Nymex Holdings ( NMX) after it and CME Group ( CME), a fellow commodities exchange, confirmed that they're in "preliminary" merger discussions with an exclusive 30-day negotiating period. Current numbers being kicked around would have CME paying $36 in cash and 0.1323 of its shares for each Nymex share -- in total, about $119.22 per Nymex share, based on CME's Friday closing price. As of Nymex's last reported share count in November, that would mean a deal worth roughly $11.07 billion. Another component to the agreement, if and when it closes, may have Nymex buying back its 816 memberships for no up to $500 million. New York-based Nymex was rising $8.26, or 7.7%, to $115.42 as Chicago's CME shed 1.8% to $617.85. Satellite radio company Sirius ( SIRI) added 19 cents, or 6.6%, to $3.08 on renewed speculation that the company's $4.6 billion bid for its rival XM ( XMSR) may be nearing regulatory approval. Sirius has been waiting for FCC approval of the purchase since it announced the deal 11 months ago. Shares of XM were up 16 cents, or 1.5%, to $11.15. Yahoo! ( YHOO) was off $1.16, or 5.3%, to $20.78, a day ahead of the company's fourth-quarter earnings report. For the fourth quarter, Yahoo! forecast revenue between $1.31 billion and $1.45 billion. It didn't offer guidance on its EPS. Yahoo posted earnings of 19 cents a share on revenue of $1.22 billion a year ago. Analysts polled by Thomson Financial expect EPS of 11 cents on revenue of $1.41 billion for the quarter. For the current quarter, analysts expect earnings of 12 cents a share on revenue of $1.37 billion. Shares of Houston-based Landry's Restaurants ( LNY) rose 22.7% to $20.45 on news that CEO Tilman Fertitta made an offer to buy the company for $1.3 billion, or $23.50 a share. The proposal represents a 41% premium over Landry's stock closing price Friday. Ceragon Networks ( CRNT) shares fell 16.9% to $8.58 on less-than-knockout fourth-quarter earnings. Non-GAAP income for the Israeli maker of point-to-point wireless backhaul solutions was $4.9 million, or 14 cents a share, in line with analysts' expectations and up from $2.7 million, or 9 cents a share, in 2006.