The energy unit of Warren Buffett's Berkshire Hathaway Inc is nearing a deal to acquire Oncor Electric Delivery Company LLC, which would allow the utility to exit a three-year-long bankruptcy, according to people familiar with the matter.

Berkshire Hathaway Energy's deal for Dallas-based Oncor would come after the Public Utility Commission of Texas (PUCT) rejected NextEra Energy Inc's previous deal to buy Oncor.

Berkshire Hathaway's deal, which could be announced by Friday, would value Oncor at slightly less than NextEra's previous $18.4 billion bid, two people said. The Wall Street Journal, which reported on the deal earlier, said it could be valued at more than $17.5 billion.

The sources asked not to be identified because the deliberations are confidential. The PUCT and Oncor did not immediately respond to requests for comment. Berkshire declined to comment.

Berkshire Hathaway had been among the leading bidders for Energy Future Holding Corp's Oncor Electric Delivery in earlier auctions for the bankrupt utility, according to the sources.

Energy Future had filed for Chapter 11 in April 2014 after it failed to meet its debt obligations as electricity prices weakened.