Market Update: Citigroup (NYSE:C), Pfizer (NYSE:PFE), Barnes & Noble (NYSE:BKS), BP (NYSE:BP), Sirius XM Radio (NASDAQ: SIRI)

Citigroup (NYSE:C) said Tuesday it will open four retail branches in Japan this year, marking its first expansion there since selling several of its Japanese finance businesses in the wake of the global financial crisis. In other news, Whirlpool (NYSE:WHR) reported Tuesday it more than doubled fourth quarter profit to $95 million, or $1.24 per share, as revenue rose 12.7% to $4.86 billion and on cost-cutting measures. Results beat estimates of $1.32 per-share on $4.44 billion in revenue. Whirlpool also guided 2010 expectations and said it is starting to see signs of business improving in North America. Shares climbed 2.8% ahead of the bell. –Daily Finance

Doctors may learn next month that Dimebon, a 27-year-old hay fever treatment and one of the most mysterious compounds yet tried to fight dementia, is poised to become their newest and perhaps best weapon against Alzheimer’s. Medivation Inc., the start-up that persuaded Pfizer (NYSE:PFE), the world’s biggest drugmaker, to help develop Dimebon, may be ready to release new research data during the first week of March, said Bengt Winblad, head of Alzheimer’s research at the Karolinska Institute in Stockholm and a leader of the European trials for the product. The study may confirm a 2008 finding in Russia that patients functioned better and thought more clearly after swallowing Dimebon tablets three times a day. -Bloomberg

Activist investor Ron Burkle sent a letter to Barnes & Noble (NYSE:BKS) seeking to acquire as much as 37% of the company, up from his current stake of 19%, and blasting the book retailer for having different sets of anti-takeover rules for big investors: one applying to insiders and one applying to outsiders. News of the letter sent Barnes & Noble shares up 18% in after-hours trading Monday. In November Barnes & Noble disclosed that its board had adopted a shareholder-rights plan, also known as a “poison pill,” in response to the recent rapid accumulation of the bookstore chain’s stock by an unnamed investor, who turned out to be Mr. Burkle. Now the billionaire and his investment firm, Yucaipa Cos., are seeking to raise their stake to 37% without triggering the shareholders-rights plan. -The Wall Street Journal

BP (NYSE:BP) on Tuesday swung to a profit in the fourth quarter, helped by rising crude-oil prices, improved production and cost cutting. BP said it swung to a fourth-quarter profit of $4.3 billion after losing $3.34 billion in the prior-year period when oil prices had plummeted. For the year, BP earned $16.58 billion, down 22% from 2008 levels and below the $19.28 billion profit of Exxon Mobil in 2009. -MarketWatch

Sirius XM Radio (NASDAQ: SIRI) was raised on its debt rating last night at Moody’s and it looks like we’ll have 52-week trading highs this morning. Shares are up 3.75% at $0.91 on 2 million shares as of 8:53 AM EST. -24/7 WallSt.

-Roundup provided by Jutia Group