NEW YORK,  (Reuters) – U.S. stocks scored their  best week since November yesterday as a broker upgraded Merck &  Co, saying its deal to buy a rival was shrewd, and Citigroup  said it did not need any more government aid.

Merck gave the Dow its biggest boost after Sanford C.  Bernstein upgraded the drug maker’s stock to “outperform,”  saying its deal to buy Schering Plough Corp would add value at  a decent price.

The S&P marked its third best week since World War II and  was initially underpinned by comments from Citigroup’s Chairman  Richard Parsons to Reuters late Thursday that the bank did not  need any more government aid, sending its stock up more than 6  percent.

An index of bank stocks rose 37 percent this week after  several top bank executives suggested the industry is  stabilizing. The comments began to reverse several months of  serious pessimism about the industry’s fate, lifting each of  the major indexes to their best week since the end of  November.      The rally in drug stocks came after sharp declines in the  sector in the wake of U.S. President Barack Obama’s budget, as  investors bet it would choke profits.