Verizon Communications Inc. is close to selling a package of wireline assets to regional telecommunications company Frontier Communications Corp. for around $10 billion, people familiar with the matter said. The deal, which could be announced this week, would be the largest ever for Frontier FTR, +5.77% , according to S&P Capital IQ. It also would be one of the largest in the U.S. so far this year, according to Dealogic. Verizon VZ, -0.06% is also close to a sale of a package of cellphone towers for around $5 billion, people familiar with that transaction said. The wireline sale would pare back Verizon’s role selling telephone and Internet service to residential customers and businesses. The company is the largest U.S. wireless operator by subscribers and sees that market as the key to its future. Selling local telephone service also is highly regulated. An expanded version of this report appears at WSJ.com.