* CFTC's Wetjen supports appealing ruling against limits
* Two other commissioners previously supported an appeal
* Next step is to formalize decision on appeal-Wetjen
CHICAGO, Nov 1 (Reuters) - A majority of the Commodity Futures Trading Commission supports appealing a judge's ruling against limits on commodity-market speculation, Commissioner Mark Wetjen said on Thursday.
The five-member commission approved position limits last year to cut down on excessive speculation in commodity markets. The rules limit the number of contracts traders can hold in 28-commodities, including oil, coffee and gold.
However, U.S. District Court Judge Robert Wilkins on September 28 sent the rule back to the CFTC for further consideration, just two weeks before limits were set to take effect. He said the Dodd-Frank financial oversight law did not give the commission a "clear and unambiguous mandate" to set position limits without showing they were necessary.
"There are three commissioners who have made it known that they support an appeal and so the next step is to formalize the decision," Wetjen told reporters on the sidelines of the annual Futures Industry Association conference in Chicago.
"I've signaled to the chairman I would be willing to support the appeal," he said.
Commissioner Bart Chilton and CFTC Chairman Gary Gensler have previously said they would support an appeal.
Lawmakers and President Barack Obama have argued that regulators should be doing more to rein in traders who may be driving up the price of oil for consumers through speculation.
But Wall Street has argued that regulators have not proven position limits would curb speculation in markets and prevent disruptive price spikes.
Critics have said position limits could inadvertently make markets more volatile, not less, because traders would move deals to overseas exchanges with looser regulations, reducing liquidity in U.S. markets. (Reporting By Tom Polansek; editing by Carol Bishopric)