WASHINGTON — Verizon reached an agreement in principle on Friday on a four-year contract with two unions representing nearly 40,000 workers who had been striking since April 13.

The two sides met on Friday to complete the agreement for ratification by the membership of the two unions, the Communications Workers of America and the International Brotherhood of Electrical Workers.

While the details were not available Friday evening, people close to the discussions said that it would include two key concessions from the company: a commitment to create about 1,500 new union positions in the United States, many of them at call centers, and the inclusion of some 65 Verizon Wireless retail workers in the new contract, a first for the company.

In a statement, Chris Shelton, president of the Communications Workers of America, said, “The addition of new, middle-class jobs at Verizon is a huge win not just for striking workers, but for our communities and our country as a whole.”