The world's biggest airline, American Airlines Group Inc., will add 90 new regional jets to its fleet, local media reported Thursday. The air carrier said it is buying 60 Embraer E175 planes valued at 2.5 billion U.S. dollars, and 30 Bombardier CRJ900 NextGen planes worth about 1.42 billion dollars, the Houston Chronicle, the largest daily newspaper in the U.S. state of Texas, reported at its website. The American Airlines Group also has options for 40 additional Bombardier jets and 90 more Embraer planes. If all of the options are exercised, the value of the total deal could top 9 billion dollars, said the report. Deliveries of the CRJ900 planes will be in the second quarter of next year, while deliveries of the E175 airplanes will take place in the first quarter of 2015. The new 76-seat jets will replace the air carrier's smaller, less efficient 50-seat regional aircraft that are scheduled for retirement, according to the report. The announcement came just days after US Airways and American Airlines' parent corporation, AMR Corp, closed a merger deal on Dec. 9 to create the American Airlines Group. Embraer, a Brazilian aerospace conglomerate that produces commercial, military, and executive aircraft and provides aeronautical services, competes with Canadian rival Bombardier for the title of the third largest airplane maker after Airbus and Boeing.