The HAGUE, Netherlands ( TheStreet) -- Royal Dutch Shell ( RDS.A) is selling assets including its European liquid petroleum gas business and mature oil and gas fields in the North Sea and Nigeria as part of its efforts to raise $2 billion to $3 billion this year to meet its $28 billion capital spending program, sources told the Financial Times. Shell is looking to sell assets not central to its growth plans including downstream assets such as refining and marketing operations in mature markets like Europe, the newspaper reports. Buyers have been invited to submit bids for the French-based European LPG business. Axa Private Equity, Bain Capital and PAI are in the running for the business. In addition, CVC Capital Partners and the Carlyle Group are also rumored to be interested. According to the Financial Times, the bids could go up to 1 billion euros. Bids are due March 22. Shell also has put up for sale North Sea fields and fields in the Southern gas basin which are operated by Shell and half-owned by Exxon Mobil ( XOM). No buyer has yet shown interest in these assets which could be valued at several hundred million pounds, the Financial Times reports. Follow TheStreet.com on Twitter and become a fan on Facebook.