A survey of agents conducted by web-centric brokerage Redfin suggests that bidding wars will increase this spring, with Boston agents among those most likely to say competition is on the rise.

Redfin polled 435 Redfin agents and partner agents in 26 U.S. markets for its survey, with 61 percent of them expecting more competition this spring than in 2013.

Agents foresee bidding wars picking up the most in the Northeast and Midwest. In Boston and Chicago, for example, homes for sale have decreased by 22 percent and 29 percent, respectively, from last year, according to Redfin’s figures.

"Bidding wars are heating up in Boston," Redfin agent Adam Welling said in a statement. "The difference this year is that competition has spread. With inventory so low, homebuyers are expanding their search, and neighborhoods that didn’t have multiple offers last year are now seeing heavy competition."

This rise in competition has sparked an increase in rent-back agreements, with home sellers negotiating for several months of lead time in order to land their own next purchase. About 63 percent of Redfin agents say they have seen more home sellers negotiating these rent-backs than last year.

Redfin agents say the cold winter affected buyer activity. In the Midwest and the Northeast, where winter temperatures and snow were the most extreme, 48 percent and 39 percent of agents, respectively, say the weather hurt buyer activity "a lot."