0515 GMT - The U.S. Treasury is expected to be more interventionist, pursuing incremental adjustments rather than dramatic changes to debt management, following the announcement of doubling long-end securities buybacks, Deutsche Bank strategists say in a note. "We also expect increased communication outside the quarterly refunding process, with Treasury using active signaling more extensively as a policy tool," they say. Treasury could leverage flexibility in the language of last week's announcement to increase long-end operation sizes beyond the initial suggested minimum of $4 billion, the strategists say. "Long-end buybacks regularly attract as much as $20 billion in offers, giving Treasury substantial scope to increase operation size in the near term." Treasury could also maintain operational flexibility by releasing its updated buyback schedule without specifying long-end operation sizes, they say.