WASHINGTON — The departure of President Barack Obama's top economic adviser at the end of the year could provide the White House with an opportunity to revamp its economic team after the November elections, when voters are expected to take out their anxieties on Democrats.

A White House official said Tuesday that Lawrence Summers, director of the National Economic Council, would leave at the end of the year to return to Harvard University. Though administration officials said Obama had known for some time Summers would depart this year, news of his pending exit comes amid deep concern over the sluggish pace of the recovery, as well as criticism of the team that conceived the administration's economic policies.

Summers was the chief architect of many of those policies, playing a central role in the massive economic stimulus and the government bailout of the auto industry.