The Washington Post Co., which owns six stations including Detroit’s WDIV and Houston’s KPRC, announced today that first quarter revenue for its broadcast division was down 2% from the same period last year.

Post stations brought in $72.2 million for the quarter, compared to $73.5 million for the first three months of 2010. Operating income for the first quarter was $19.6 million, a 6% decrease from the previous year.

WDIV and KPRC are both NBC-affiliates and the company attributed the dip in first quarter revenue to the absence of the extra $4.7 million those stations brought in around last year’s Winter Olympics. As well, Post stations saw a $1.8 million decrease in political advertising compared to Q1 last year.

Overall, the company sustained a 67% drop in first quarter profits as revenue for its Kaplan education unit, currently under government scrutiny, declined sharply.