Hunt Valley-based Sinclair Broadcast Group Inc. said Wednesday second quarter profit rose to $17.3 million, or 21 cents per share, up from $2.8 million, or 4 cents per share, for the same period a year earlier, as sales of television advertising continued to improve.

Net broadcast revenues from continuing operations jumped more than 19 percent in the three months ended June 30, rising to $158.7 million from $133 million, the company reported.

"Broadcast television advertising continues to grow, an indicator that the economy is showing signs of recovery," David Smith, president and chief executive officer, said in a statement.

Smith said the broadcaster, owner and operator of 58 U.S. television stations, showed gains in nearly all the main advertising categories, with the biggest increase, of 46 percent, in automotive advertising. Political advertising so far this year is ahead of the first six months of 2006, which is the last time sales didn't see a boost from presidential ads, Smith said.

Political advertising rose as well in the second quarter, to $3.8 million compared with $700,000 in the second quarter of 2009.

Other advertising categories where spending increased included schools, media, medical and furniture. But advertising sales fell in the paid programming and fast food categories, the company said.

David Amy, chief financial officer, said the company expects less growth in sales from core advertisers in the second half of the year as many of them will be pushed out of advertising space by spending by political candidates and campaign issues.