NEW YORK: Oil was on course to its best monthly gain in six years, with the two global benchmarks poised to finish up 20 percent or more for April, helped by a weaker dollar and bets that a supply glut would ease.

After the June-till-January selloff that halved oil prices from highs above $100 a barrel, Brent and US crude had their strongest recovery this month, gaining about $11 each, and hitting their highs for 2015.

In Thursday’s session, Brent was up 60 cents at $66.44 a barrel by 11:12 a.m. EDT (1512 GMT). It hit the year’s peak of $66.72 on Wednesday.

US crude CLc1 rose 45 cents to $59.03, after soaring to a 2015 high of $59.40 earlier in the session.

The gains came as the dollar fell to a February low, making oil less expensive to holders of other currencies.

Crude’s percentage gains in April were the best since May 2009, when prices were just recovering from the financial crisis, and backed oil bulls’ contention that the supply-demand imbalance would level.

But some were skeptical of a smooth continuation to the rally, citing disappointing US economic growth in the first quarter.

“It seems more likely that we will hit some speed bumps on this rally, given the unrelenting OPEC supply and the uneven US economic data, which could cause dollar gyrations,” said John Kilduff, partner at New York energy hedge fund Again Capital.

The dollar came off its lows on Thursday after US economic data showed consumer spending rose in March and jobless claims hitting 2000 lows.

A Reuters survey of 32 analysts predicted Brent would average $60 in 2015, up 80 cents from last month’s survey, while US crude was seen at $54.40 versus $53.60 previously.