A Gallup poll based on interviews with voters Wednesday, Thursday and Friday found Obama preferred by 49 percent of those surveyed, compared to 41 percent for Obama, Gallup said.

Obama's 49 percent figure tied his high during the campaign so far. It reflects a boost in the polls for the Illinois senator during the weeklong Democratic National Convention in Denver.

The Friday interviews were conducted after Obama accepted the nomination in a nationally televised address Thursday.

The Friday surveys also followed presumptive Republican nominee John McCain's announcement of Alaska Gov. Sarah Palin as his running mate.

The Republican National Convention is scheduled to run Monday through Thursday in St. Paul, Minn. McCain's polling numbers may increase during the convention - however, party officials are considering postponing the convention depending on how Hurricane Gustav affects the Gulf Coast.

The results are based on a sample of 2,709 registered voters and the maximum margin of sampling error is plus or minus 2 percentage points.