SoftBank is gearing up for an expected lengthy regulatory review of its rumored bid to merge Sprint and T-Mobile. Lenders are demanding higher fees for financing the deal to offset the review process that could last at least a year, according to Bloomberg.

Earlier reports said SoftBank and Sprint have already lined up eight banks to help finance their bid to purchase a controlling share of T-Mobile from Deutsche Telekom (DT), which holds a 67-percent stake in the U.S.’s fourth biggest carrier.

Part of the money Sprint and SoftBank are requesting from lenders is being earmarked for spectrum. The report said Sprint and T-Mobile will enter into a separate joint venture and bid on spectrum available in upcoming FCC auctions.

The Bloomberg report cited unnamed sources who said SoftBank set a termination date for the deal at 18 months after it’s announced but that deadline could be extended.

U.S. federal regulators shut down AT&T’s 2011 bid for T-Mobile and have thus far voiced similar skepticism about Sprint and T-Mobile merging. SoftBank and DT reportedly have already talked about challenging should the FCC and Department of Justice move to block the rumored merger.

A Nikkei report surfaced last week suggesting SoftBank and DT have reached a “basic agreement” on terms for the proposed merger.