It didn't cite Libby for outing Plame. From <a href="http://www.cnn.com/2005/POLITICS/10/28/leak.probe/>CNN

Libby resigned Friday after a federal grand jury indicted him on five charges related to the leak probe: one count of obstruction of justice, two counts of perjury and two counts of making false statements.

Following the Charges Explained link:

Count one: Obstruction of justice
Alleges that Libby intentionally deceived the grand jury about how he learned, and "disclosed to the media," information about Valerie Plame Wilson's employment by the CIA.

Obstruction of justice is interference in one of the three branches of government. It can include improperly influencing a juror, stealing or altering a record and obstructing a criminal investigation.

Count two: Making a false statement
Alleges that Libby intentionally gave FBI agents false information about a conversation he had with NBC's Tim Russert regarding Valerie Plame Wilson, who is married to Joseph Wilson.

This crime covers activities that might not be illegal if not for associated false statements. To convict on a false statement charge, prosecutors must prove the defendant willfully lied or concealed a fact.

Count three: Making a false statement
Alleges that Libby knowingly gave the FBI false information about what he had told reporter Matt Cooper of Time magazine regarding Valerie Plame Wilson.

Count four: Perjury
Alleges that Libby knowingly provided false testimony in court about a conversation he had with Russert.

Perjury is willfully or knowingly making false statements under oath. The sworn statements may be written or oral and need not be made in court. They may be made in a deposition or in written testimony. To be convicted, prosecutors must prove the accused intended to give a false statement. Making a mistake does not constitute perjury. Also, a person can be convicted of perjury if it can be proven he or she gave contradictory statements. It is not necessary to prove which statement was false.

Count five: Perjury
Alleges that Libby knowingly provided false testimony in court about his conversation with reporters regarding Valerie Plame Wilson's CIA employment.

Pleae note how none of these charges refer to him revealing Plame's name. As for why the CIA requested the investigation, I don't know. Perhaps they made the request without fully checking the facts.