Informix error -346

An ESQL/C program, which processes a huge amount of data in one single transaction, causes the SQL-error Code -346. I use Informix-SE INFORMIX-SE Version 7.10.UD1, on a Unisys SMP5400 Unix machine. Could someone confirm or explain that the error is caused by a 'too large' transaction!? How can I determine the size of a transaction, and how to put more updates and inserts into 1 single transaction!? (enlarge a transaction) If possible, I do not want break-down the workload into smaller transactions. Please advice! Many thanks, Hal van den Assem