Citigroup ( C) disclosed Friday it is in talks with securities and bank regulators about a transaction it had with Dynegy ( DYN). In its 10-Q report filed with the SEC, Citigroup said the discussions with power company Dynegy arose out of talks over certain transactions it had with ill-fated Enron, Dow Jones reported. Citigroup provided no further information. Shares of Citigroup closed higher by 70 cents, up 1.79%, to $39.70. Dynegy, which has been enjoying a resurgence lately, saw its shares finish up 9 cents, or 2.08%, to $4.41.