British defence group BAE Systems on Wednesday warned that a lucrative deal to sell fighter jets to Saudi Arabia was facing unresolved "issues" five years after an agreement was struck between the two sides.

BAE and Saudi Arabia signed a �4.5-billion ($7.3-billion, 5.5-billion-euro) deal in 2007 to supply 72 Eurofighter Typhoon planes to Riyadh.

"Discussions with the Kingdom of Saudi Arabia government have been underway for some time to agree definitive pricing for the supply of 72 Typhoon aircraft to the Royal Saudi Air Force (RSAF) contracted in 2007 under the government-to-government Salam programme," BAE said in a statement on Wednesday.

"Whilst progress has been made through the course of these negotiations, issues remain to be resolved before contract pricing, acceptable to all parties, can be agreed."

BAE, which earlier this year failed to cement a merger deal with European aerospace giant EADS, added that discussions would continue towards an agreement.

"Acceptable pricing terms remain the group's driver to such an agreement, not the timing of the settlement," it said.

BAE's share price was down 1.0 percent to 342.30 pence after the company announcement and in late trading on London's FTSE 100 index of leading companies, which was 0.55-percent lower at 5,968.99 points.