By Selina Williams

LONDON--A top BP PLC executive is in advanced negotiations to become chief executive of U.K. utility Centrica PLC (CNA.LN), the BBC reported on its website Wednesday.

Iain Conn, currently the head of BP's downstream operations, is on a "shortlist of one" to succeed Centrica's current Chief Executive Sam Laidlaw the BBC reported, citing sources. Mr. Laidlaw is looking to step down after eight years as Centrica's CEO.

Centrica and BP declined to comment on the BBC report.

Mr. Conn would be taking the helm at Centrica at a difficult time for the company following the departure of several members of its top management team and political criticism over high energy bills. The U.K.'s competition authority is meanwhile investigating the country's energy market. That probe comes after an investigation by energy regulator Ofgem this year said the U.K.'s six biggest electricity suppliers' ownership of both power stations and supply businesses made it difficult for new entrants to compete in the sector.

Mr. Conn has been in charge of BP's refining and marketing, or downstream, group since 2007, a period of declining profits throughout the industry. BP's own downstream profits have fluctuated due partially to the results of its trading arm, which the company doesn't publicly detail.

Before heading BP's downstream operations, Mr. Conn led BP's petrochemicals group and before that it's European marketing operations. Mr. Conn, 51, joined BP in 1986. He also serves as a director of BT Group PLC.

His arrival at Centrica wouldn't be the only change in its top ranks this year. The head of its international downstream arm, Chris Weston, said in May he would be leaving the company. Mr. Weston had been touted as the top internal candidate to take over as CEO. Finance Director Nick Luff in January said he would leave the company this year, while its head of mergers and acquisitions Russell Alton also said last month he was leaving.

Centrica is due to report weak earnings for the first half of the year next Thursday due to unseasonal weather in the U.K. and U.S., according to consensus estimates.

Justin Scheck in London contributed to this article.

Write to Selina Williams at selina.williams@wsj.com

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