By Pratish Narayanan and Emily Chasan

MUMBAI/NEW YORK (Reuters) - LyondellBasell has rejected an offer from Reliance Industries' that values the bankrupt petrochemicals group at $14.5 billion, a person familiar with the matter said on Tuesday.

This is the third advance that Lyondell's board has rejected from Reliance over the past year in a decision that could leave the Indian energy group having to look elsewhere for takeover targets.

In rejecting the offer, Lyondell did not give any details about whether further negotiations would be fruitful, this person said, declining to be named because the negotiations are not public.

Reliance, controlled by India's richest man, Mukesh Ambani, has said his company plans an aggressive exploration campaign, investments in petrochemicals and overseas acquisitions.

It was not clear whether Reliance, which has raised a war chest for deals by selling $2 billion of stock in recent months, would continue its pursuit of the petrochemicals maker. A Reliance spokesman declined to comment.

Lyondell spokesman David Harpole also declined to comment but said a new disclosure statement about the company's current proposed reorganization plan will be filed with a United States court imminently.

A creditor group led by U.S. private equity firm Apollo Management, which is controlling Lyondell's bankruptcy process in the United States, was expected to file a reorganization plan on Monday. That plan is intended to lead Lyondell out of bankruptcy.

Shares of Reliance, India's most valuable listed company with a market value of about $70 billion, closed 0.6 percent higher on Tuesday, underperforming the 2.1 percent gain in the benchmark index.