Telecommunications gear maker Lucent Technologies Inc. may receive an $816 million federal income tax refund related to its multibillion dollar losses during the telecom industry slump.

Lucent filed a document yesterday with the Securities and Exchange Commission stating the Internal Revenue Service has tentatively approved a claim for what is called a net operating loss carry back. The claim covers Lucent’s 2001 fiscal year, when the Murray Hill, N.J.-based company reported a net loss of $16.2 billion.

Under federal tax rules, companies can take net operating losses from one fiscal year, carry them back to a prior, profitable year and deduct the losses from that year’s profit. Lucent wanted to carry back to its fiscal 1996 year its net operating loss from 2001.

In the brief SEC report, Lucent stated that it filed the claim on September 30, 2003, and IRS initially denied all but $139 million. Lucent appealed. On Wednesday, Lucent wrote, it reached a tentative agreement with the IRS that al lows a carry back that will result in a cash refund of approximately $816 million.

“We’re happy to be talking about it today, but it’s still got some hurdles,” said Lucent spokesman Bill Price.

Those include an IRS audit needed for final approval by that agency and approval by the Congressional Joint Committee on Taxation. Lucent said it anticipates the refund, plus an undetermined amount of interest, will be received during its 2005 fiscal year, which begins October 1.

The $16.2 billion net loss in 2001 was the largest of three straight annual losses during a period when Lucent’s sales plunged and it eliminated or spun off about three-quarters of its work force.

The net operating loss, the figure reported on Lucent’s income tax return, differs from the net loss on its profit and loss statement because of accounting variations. Lucent is not disclosing the 2001 net operating loss, but Mr. Price said the company and a cumulative federal net operating loss of about $10.5 billion as of last September.