Rep. Harold Ford, a Democrat, is running even with Republican Bob Corker in Tennessee, while Democrat Jon Tester has edged ahead of Senator Burns in Montana, according to polls released yesterday for some of the most contested Senate races. The findings suggest an intensely competitive campaign for Congress heading into the November 7 elections.

Republican Senator DeWine is in a virtual tie with Democratic Rep. Sherrod Brown in Ohio.

The three races are three that Democrats need to win if they are to take control of the Senate.

The Mason-Dixon polls done for various journalistic outlets found:

• Mr. Ford had the backing of 43% in Tennessee, while the former mayor of Chattanooga, Tenn., Mr. Corker was backed by 42%.Mr. Corker had a lead in midsummer polling matching the two.

• Mr. Tester has pulled ahead of Mr. Burns in Montana, by 47% to 40%. They were tied in August polling.

• Mr. Brown had 45%, and Mr. DeWine had 43% in Ohio, findings similar to those of a Quinnipiac poll released a week ago.

The polls were conducted for MSNBC, McClatchy Newspapers, and newspapers in each of the states — the Plain Dealer of Cleveland, the Lee Newspapers in Montana, the Commercial Appeal of Memphis, Tenn., and Chattanooga Times Free Press in Chattanooga, Tenn.

The polls of 625 registered voters in each state were conducted September 25–28. They had margins of sampling error of plus or minus 4%.