WASHINGTON (Reuters) - Republican Mitt Romney has erased U.S. President Barack Obama's advantage in the presidential race and the two candidates are now tied among likely voters, according to a Reuters/Ipsos tracking poll released on Tuesday.

With the November 6 election four weeks away, Romney and Obama each command 45 percent, the daily tracking poll found.

Obama held a steady lead in the poll for most of September, but Romney narrowed the gap following a strong debate performance last week. Obama had been leading by 2 percentage points in the last poll on Sunday.

Voters' personal views of Romney improved across a wide range of attributes following the debate, the poll found.

The online survey of 1,157 likely voters was conducted between October 5 and October 9. The precision of the poll is measured using a credibility interval, which is plus or minus 3.3 percentage points.

(Editing by Doina Chiacu)