PARIS – A 12-year corruption investigation in France that at one stage threatened to engulf President Chirac ended yesterday in fines and minor convictions for a group of businessmen, consultants, and council housing officials, but not a single politician.

In all, 37 of the 49 defendants were convicted, receiving suspended sentences of between two months and two years and fines ranging from $3,600 to $72,000.

The verdicts were the culmination of a fierce, decade-long legal battle that demonstrated the limited power of French judges over top politicians. Investigating magistrates were never able to bring to book the alleged political masterminds behind the scam, despite damning testimonies.

Investigators into the so-called “affaire des HLM de Paris,” or Paris council housing scandal, had sought to lay bare a complex system of bribes by companies in return for public contracts that operated between 1987 and 1993. when Mr. Chirac was mayor of Paris.

The mechanisms behind the scandal were explained during the 2 1/2 month trial in Paris’s criminal court. Building and maintenance companies paid bribes to the Paris council housing authority, OPAC, to secure lucrative contracts.

In turn, many of those implicated had claimed, the bribes ended up either in Mr. Chirac’s now defunct Gaullist RPR Party coffers or in corrupt politicians’ foreign bank accounts. But investigators were unable to unravel a web of offshore accounts and international bank transfers to confirm the claims and implicate the beneficiaries.

The HLM de Paris investigation began in 1994, after tax inspectors came across $3.6 million in bogus bills paid by a building repair company run by a Gaullist friend of Mr. Chirac’s, Francis Poullain, to a “consultant” and member of the RPR’s real estate committee, Jean-Claude Mery.