Herbert Smith Freehills (HSF) and Simmons & Simmons are among the firms that have been invited to bid for spots on state-owned Qatar Petroleum's (QP) first legal panel, Legal Week has learned.

Simmons energy partner Adrian Nizzola, who was general counsel for QP between 2000 and 2003, confirmed that his firm had been sent a "request for proposal (RFP)" by QP to "establish a formal legal panel".

Nizzola said the client had not yet set a timescale for how long the roster would be in place.

The company is understood to have sent RFPs to several firms.

"They sent out a lot of RFPs, more than people perhaps thought," said a Qatar-based partner at an international firm. He added that law firms are unlikely to hear a response from QP until the end of the Islamic holy month of Ramadan, which began on 18 June and runs until 17 July.

It is understood that HSF, which opened in Doha in 2012 and has advised QP since 2002, has already submitted a proposal.

Simmons declined to comment on whether it had submitted a proposal. The firm opened an office in Doha in 2003 and was the first international firm to be granted a licence to operate independently in Qatar advising on both Qatar and international law matters.

It has been instructed by the oil company since 2008 on a 'call off basis', according to Nizzola.

White & Case has advised the company since the 1990s and opened an office in the Qatari capital in 2009 on the back of its relationship with QP. The firm declined to comment on whether it was involved in the panel contest.

The Qatar-based partner said QP previously opted to use a "group of individuals" rather than specific firms, adding: "They kept utilising those individuals."

For example, Nizzola has provided ongoing senior legal support to QP for more than 17 years – including his time at the company – and HSF construction partner James Bremen has advised the company for 13 years.

A second Qatar-based partner said "procurement methods are changing" in the country and it is becoming more common for Qatari companies to have panels in place. He added that many clients are moving towards having a "preferred supplier type of approach".

Simmons, HSF and White & Case have continued to advise QP this year. However, they declined to provide any further details on the deals because of confidentiality agreements with the client.

The most recent transaction announced by one of the trio saw HSF act for Qatar Petroleum International, a subsidiary of QP, on its acquisition of a 15% stake in oil company Total E&P Congo in 2013. The deal, worth $1.6bn (£962.9m), was part of a wider agreement signed by the two companies to cooperate on projects in Africa.

QP did not respond to a request for comment.