Green Dot Corp. late Wednesday completed its acquisition of Loopt, a Mountain View mobile social networking developer, for $43 million cash. It is Green Dot’s biggest purchase.

The Monrovia provider of prepaid debit cards wants to use Loopt’s technology to help its development of a so-called mobile wallet, which allows customers to make purchases through their smart phones. Green Dot said Loop not only provides it with innovative mobile social networking software, but also a team of developers to design new products. Loopt’s operations will remain in Mountain View.

Green Dot has made several strategic acquisitions in recent months. In January it acquired the assets of eCommLink, a Las Vegas firm that processes card payments, which should enable the Monrovia company to save money on transaction processing.

In December it bought Bonneville Bancorp. Renamed Green Dot Bank, the Provo, Utah institution now is being used to issue and administer most of the company’s debit cards.

Shares were down 26 cents, or 1 percent, to $28.81 in Thursday midday trading on the New York Stock Exchange.