The Securities and Exchange Board of India (Sebi) rejected Reliance Industries Ltd's request to settle a long-pending dispute over the energy conglomerate's 2007 sale of stock futures in a unit, citing rule changes in late May that took a tougher stance on suspected violations.

The SEBI included Reliance Industries and a handful of its units on a list of 149 companies or individuals whose requests to settle market rules violation cases with financial payments had been rejected, a notice issued late on Thursday showed.

A Reliance spokesman declined to comment on the SEBI announcement.

The dispute with Reliance stems from SEBI's investigation into suspected insider trading when the energy conglomerate sold stock futures of Reliance Petroleum before folding the unit into its operations.

Reliance Industries has denied engaging in any insider trading in that transaction.

SEBI amended its procedures for so-called consent applications, or requests for out-of-court settlements, in May 2012, effectively banning the use of monetary payments to resolve suspected cases of market rule violations, including insider trading.

The regulatory changes followed criticism that consent orders were being inappropriately used by those under investigation to avoid potentially more damaging rulings by the regulator on wrongdoing.

Uncertainty had remained, however, over whether consent applications such as Reliance Industries' that were submitted before the rule change would be allowed to go ahead.

Although the possibility of a settlement under the old consent applications has been removed, the regulator's brief statement said only that proceedings would continue in accordance with the law, offering no clues on how much longer the case might drag on.

Reliance shares in Mumbai had edged down 0.4 percent as of 1:25 p.m., compared with a 0.5 percent gain in the NSE's energy subindex.