DUBAI, June 1 (Reuters) - Stock markets in the Gulf may trade with a weak bias on Wednesday as investors may continue to book profits in the absence of positive catalysts.

Brent oil futures LCOc1 are trading at $49.51 per barrel in early Asian trade, down 0.8 percent.

Despite mixed performances on Tuesday, all major Middle East bourses ended with losses for the month of May, with Riyadh's index .TASI the top loser, down 6.5 percent in May.

The banking sector was the main reason for the index's worst monthly peformance since January, with the sub-index .TGFSI down 6.8 percent; investors may stay clear of long-term positions in those shares until the banks' next quarterly results are out.

"Though banking Q1 earnings fared better than expected, the future looks less promising as provisions and non-performing loans will likely pick up, especially from the negative knock-on effect from the contracting construction sector," said a Dubai-based analyst.

Dubai's index .DFMGI last at 3,314 points, faces resistance at the mid-May high of 3,373 points, from which it retreated earlier this week.

"If the resistance holds strong...we may see sideways momentum in the near term. A break above will form a bullish reversal, targeting the 3,420 barrier," said a note by NBAD Securities.

(Reporting by Celine Aswad; Editing by Andrew Torchia) ((celine.aswad@thomsonreuters.com; +971 4 4536886; Reuters Messaging: celine.aswad.thomsonreuters.com@reuters.net))