NEW YORK (Reuters) - Delta Air Lines Inc <DAL.N> said on Wednesday the Air Line Pilots Association (ALPA) has informed the company that Delta pilots have approved a modification to their current contract.

Delta said the agreement marks an important step toward its proposed merger with Northwest Airlines Corp <NWA.N>.

Delta agreed to buy Northwest in an all-stock deal on April 14.

"The agreement facilitates the realization of revenue synergies from the combination of Delta and Northwest Airlines, once the merger is completed," said Delta in a statement.

Lee Moak, chairman of the Delta chapter of ALPA, told members in a letter on Wednesday the union looked forward to working with Northwest pilots on a "new joint agreement providing immediate parity in rates of pay" and on a rapid completion of a "fair and equitable integrated seniority list."

Pilots at Northwest opposed the merger when it was announced.

Also on Wednesday, an influential lawmaker on aviation affairs said Delta's proposal to buy Northwest is likely to be approved by the U.S. government.

Rep. John Mica, a Florida Republican and former chairman of the House of Representatives aviation subcommittee, told a hearing on the merger proposal the deal to create the world's biggest airline did not appear anti-competitive.

(Reporting by Mark McSherry, editing by Richard Chang)