Clearwire disclosed in a securities filing on Friday that it had received an offer from an unnamed company for use of its spectrum. According to The Wall Street Journal, Verizon is behind the proposed deal and has offered $1.5 billion to lease Clearwire’s spectrum. Verizon is said to be interested in Clearwire spectrum in big markets to help it bolster its 4G LTE service. The carrier is expected to face a few obstacles, however. Wireless rival Sprint has a controlling stake in Clearwire and recently proposed a takeover of the company, while at the same time Sprint is in the middle of dealing with its own merger offers from Japanese carrier SoftBank and from Dish Network. Clearwire, Sprint and Verizon, nevertheless, will come together to evaluate the offer and discuss it in further detail.