MIKA Brzezinski, the striking, blonde CBS anchorwoman who appeared to be on the fast track, is leaving the network, according to authoritative reports.

The 39-year-old daughter of former Carter White House national security adviser Zbigniew Brzezinski had been a substitute anchor for CBS on weekends and a regular correspondent for the evening news program.

She was touted as one of the network’s most-promising stars when she returned to CBS in 2001 for a second tour of duty after a short stint at MSNBC.

But in the year since the departure of Dan Rather and a change in top executives at CBS News, she has been finding it difficult to get on the air, according to a report on the Web site TVNewser.com.

She is married to Ch. 7 reporter Jim Hoffer.