UPDATE 1-MSNBC leads cable networks in Georgia election coverage

(Adds ratings data)

LOS ANGELES, Jan 6 (Reuters) - Comcast Corp’s MSNBC led primetime cable news ratings on Tuesday as election returns rolled in from the crucial U.S. Senate races in Georgia, Nielsen ratings data showed.

Roughly 4.7 million people on average watched MSNBC’S coverage from 8 p.m to 11 p.m. Eastern time, Nielsen data showed.

That was ahead of the 4.3 million people who tuned in to Fox Corp’s Fox News Channel. AT&T Inc’s CNN finished third with an average of 3.9 million.

CNN led the pack among people age 25 to 54, the key group for cable news advertisers, averaging 1.4 million viewers in that demographic.

The tight races left the networks unable to project winners during their primetime coverage. It was not until Wednesday that news outlets predicted that Democrats would take both seats, giving them control of the U.S. Senate.

Reporting by Lisa Richwine Editing by Chris Reese and Aurora Ellis