TREASURIES-Bonds rally as stocks slip, Fed buys bonds

* Bonds rally as stocks move lower

* Fed buys $7.37 billion more in Treasuries

* Investors nervous ahead of key bank earnings (Adds analyst comments, Fed purchase details, updates prices)

By Pedro Nicolaci da Costa

NEW YORK, April 13 (Reuters) - U.S. Treasury debt prices rose on Monday as stock markets veered lower ahead of a week packed with corporate earnings while the Federal Reserve stepped up direct purchases of government bonds.

Equity markets were nervous about a slew of results from companies including big financial firms such as Citigroup (C.N: Quote, Profile, Research), JP Morgan (JPM.N: Quote, Profile, Research) and Goldman Sachs (GS.N: Quote, Profile, Research). The market was also perturbed by a report that the U.S. Treasury has directed General Motors GM.N to prepare for a bankruptcy filing.

All of this made for solid gains in the bond market, which was also helped by news the Fed had bought $7.37 billion in Treasury securities.

"What added fuel to the fire was the Treasury purchases by the Fed," said Bulent Baygun, head of U.S. interest rate strategy at BNP Paribas in New York.

The Fed's buying was concentrated in notes maturing between March 2011 and April 2012. This left benchmark 10-year notes US10YT=RR 17/32 higher in price for a yield of 2.86 percent, down six basis points from where they ended on Friday. The 30-year bond US30YT=RR was up 23/32 to yield 3.71 percent versus 3.75 percent Friday.