Qatar Petroleum has chosen HSBC to advise it on the sale of its Al Shaheen Holding subsidiary, three sources with knowledge of the matter said, as it seeks to cut costs in response to lower oil prices.

The chief executive of the state-owned Qatari firm said in June it would reduce staff numbers as part of a restructuring, which would also see it exit all non-core businesses.

Among these businesses is Al Shaheen, a holding company fully owned by Qatar Petroleum and which has three joint ventures in the oilfield services industry.

Two of these are with GE Oil and Gas and one with the Middle East unit of Weatherford.

Qatar Petroleum did not immediately respond to a request for comment.

HSBC has begun offering the stake to prospective buyers, according to the sources who spoke on condition of anonymity as the information isn't public.

Two of the sources said initial meetings had been held with buyers but it was unclear whether there were any bids currently on the table. One of them added the stake was being marketed purely to international investors.

Much like Qatar Petroleum, national oil companies in the Gulf have been cutting back on spending to cope with the new lower oil price environment. Oman Oil said earlier this week it would restructure its business and sell some assets.

None of the sources would give a value for Al Shaheen, which was set up in 2006 to "develop a leading national energy services provider" according to its website.

Qatar Petroleum has already folded its foreign investments arm into the parent firm. Bloomberg also reported that it and Centrica planned to sell out of its natural gas venture in Canada.

"They are rationalising a lot of stuff as when there's a lot of cash around they can spread themselves widely, but now they are having to decide what they really are and what their strategy will be," said the third source.-Reuters