BERLIN, Dec 23 (Reuters) - Swiss building materials company Holcim (HOLN.S) said on Thursday it was to buy residential roofing maker Malarkey Roofing Products in a deal valued at $1.35 billion to expand into the growing U.S. residential roofing market. Holcim said it expects the all-cash deal to generate annual synergies of $40 million from the third year after the transaction closes in the first quarter of 2022, and start adding to the group"s earnings from the first year.