(Reuters) - The Securities and Exchange Commission wants American banks to publish more details about their exposure to European sovereign debt, a factor in the recent bankruptcy of the futures brokerage MF Global Holdings Ltd (MFGLQ.PK).

In guidance issued on Friday, the regulator's Division of Corporation Finance said disclosures by publicly traded financial institutions have been "inconsistent in both substance and presentation."

It said this could make it harder for investors to discern how much risk the banks are taking, both individually and relative to each other, and how the exposures will affect operating results or financial health.

The SEC urged that banks reveal direct and indirect exposures "separately by country, segregated between sovereign and non-sovereign exposures."

It said they should also provide more details on hedging, and the sums they might need to raise if forced to close out their positions.

"In determining which countries are covered by this guidance, registrants should focus on those experiencing significant economic, fiscal and/or political strains such that the likelihood of default would be higher than would be anticipated when such factors do not exist," the SEC said.

An SEC spokesman declined to comment. The guidance is not a rule or regulation that banks must follow.

The SEC is trying to learn more about some of the more opaque means that banks use to reduce the risk of credit losses, including derivatives and off-balance-sheet financings. This could reduce the threat of further liquidity shortfalls.

MF Global filed for bankruptcy protection on October 31 after a liquidity crunch spurred by investor and customer worries about its $6.3 billion bet on sovereign debt from Belgium, Ireland, Italy, Portugal and Spain.

The New York-based company had revealed that exposure the prior week. Its chief executive Jon Corzine, a former New Jersey governor, stepped down from MF Global's helm on November 4.

(Reporting by Jonathan Stempel in New York; Additional reporting by Carrick Mollenkamp; editing by Carol Bishopric)