Sprint Corp. and T-Mobile US Inc. could opt for an all-stock transaction if the companies agree to merge, Bloomberg News reported June 5, citing people familiar with the matter.

According to the report, parent companies Deutsche Telekom AG and SoftBank Group Corp. have yet to decide about merging the two companies, and Sprint and T-Mobile are also in talks with other potential merger partners.

Under one scenario, the U.S. carriers could set an exchange ratio that would give Deutsche Telekom a "slightly higher percentage" of the company than SoftBank, the sources said.

Another proposal being considered would allow the companies to create a holding company that would allow Deutsche Telekom to consolidate the new entity's earnings.