The Financial Industry Regulatory Authority said it fined several Wells Fargo & Co. businesses, RBC Capital Markets, LPL Financial and others a combined $14.4 million on Wednesday for record-keeping problems that may have allowed company and customer documents to be altered.

The securities industry’s self-regulator found that the firms failed to keep hundreds of millions of electronic documents in a “write once, read many” format, which would have made it impossible to alter or destroy records after they were written.

The firms agreed to the fines but neither admitted nor denied the charges.

FINRA did not say documents had been changed but said the records were “pivotal to the firms’ brokerage businesses,” and that it relies on these files to ensure firms are following securities laws.

The regulator said it also is concerned about the security of the records because hackers in recent years have aggressively targeted banks’ electronic storage databases.

The regulator fined Wells Fargo’s securities and prime brokerage businesses $4 million, and the bank’s brokerage and independent wealth management businesses $1.5 million. FINRA also fined RBS Securities, SunTrust Robinson Humphrey, Georgeson Securities Corp. and PNC Capital Markets amounts ranging from $2 million to $500,000.

Wells Fargo spokeswoman Elise Wilkinson said the firm took record-keeping compliance seriously.

“We self-reported these issues to FINRA and continue to remediate as agreed,” she said in an emailed statement.