LONDON (Reuters) - British Airways has signed a revenue-sharing agreement with Qatar Airways, allowing the pair to co-operate on scheduling and pricing, BA's owner IAG (>> International Consolidated Airlns Grp SA) said in a statement on Wednesday.

State-owned Qatar Airways owns 20 percent of IAG as a result of a stake it has been building since 2015, and the companies had said further commercial agreements between the groups could come as a result of that investment.

Airlines often use revenue-share deals where they carry each other's passengers on certain routes, giving customers a greater choice of flights and generating cost and revenue synergies for the carriers.

IAG already operates such a deal with American Airlines Group (>> American Airlines Group Inc) on the North Atlantic, for example.

IAG chief executive Willie Walsh said in a statement that the tie-up followed a deal IAG Cargo had signed with Qatar two years ago.

"It will also allow us to provide easier journeys with better aligned schedules, more frequencies and improved flight transfers," Walsh said of the new deal.

(Reporting by Sarah Young, editing by Paul Sandle)