Home prices fell another 2% in February with declines in all 27 markets tracked by Altos Research. The company said prices are slowly improving and housing inventory is up 3.75% nationwide as the market moves into a much-anticipated spring selling season.  The inventory of homes for sale declined sharply over through the holiday season, Altos said. Prices were down significantly in San Francisco and Washington in February while the listing inventory in the two cities increased, likely indicating sellers are bringing properties to market ahead of an expected uptick in buyer activity, according to Altos. “While the headline pricing metric 90-day rolling average still shows monthly declines, week-over-week data are beginning to show signs of improvement, indicating a good start to what is, typically, the strongest sales period of the calendar year” the analytics firm said. Altos said its 10-city composite index decreased just more than 2% last month to nearly $433,600 and is now down 3.4% over the past three months. There are considerable home price declines in some markets since November, but “the short-term information likely paints a more accurate picture of conditions moving into spring.” On Monday, Freddie Mac said fourth-quarter home prices fell 4.3% from a year earlier as foreclosures and slowing sales buoyed inventory levels. In early January, Clear Capital said home prices ended a turbulent 2010 down 4.1% from the year before. The analytics firm expects another decline of 3.6% in 2011. Write to Jason Philyaw.