UPDATE 2-SocGen says rogue trader Kerviel may have had help

(Adds further detail on evidence of collusion, background)

By Sudip Kar-Gupta

PARIS, May 23 (Reuters) - Societe Generale (SOGN.PA) trader Jerome Kerviel may have had internal help when he built up massive stock market bets that led to the world's worst trading scandal, a report published by the French bank said on Friday.

The report also blamed weak supervision and poor control systems for the rogue trading scandal which shook the world's banking establishment earlier this year.

The internal report said Kerviel, the junior trader blamed by France's second-biggest bank for $7.7 billion in trading losses, may have been helped by an assistant but added there was no conclusive proof of this.

"We have discovered indications of internal collusion involving a trading assistant, a middle office operational agent," said the report.

"Due to the current on-going criminal investigation, we have been unable to question this employee on this subject. The possibility of such internal collusion must therefore be confirmed by the courts," it added.

The bank has consistently said Kerviel acted alone.

The internal report, the second published by SocGen into the debacle, said the unidentified assistant had manually entered a large number of fraudulent transactions done by Kerviel.

It said the assistant registered "several abnormally high intra-monthly provision flows, without having obtained any valid explanations as to their validity."

It added that the assistant had registered a total of almost 15 percent of Kerviel's fictitious trades.

MANAGEMENT BLAMED

On Jan 24, SocGen unveiled 4.9 billion euros ($7.7 billion) of losses which it said were caused by rogue deals carried out by Kerviel.

Kerviel was freed from prison in March after an appeal against his detention but he remains under formal investigation for breach of trust, computer abuse and falsification.

A previous report by SocGen had investigated how Kerviel managed to build up a trading position of 50 billion euros - more than the stock market value of SocGen -- without getting noticed by his managers.