LendingClub Corp., the largest U.S. peer-to-peer lender, is planning an initial public offering in the second half of the year and may raise about $500 million, people with knowledge of the matter said.

The company, which named former Morgan Stanley Chief Executive Officer John Mack to its board two years ago, is working with Morgan Stanley and Goldman Sachs Group on the offering, said the people, who asked not to be identified because the process is private.

LendingClub connects individuals and institutions to borrowers via the web in return for a yield above U.S. 10-year Treasuries. The Securities and Exchange Commission requires that issuers of securities register with the regulatory agency, so LendingClub's financials are already public. The San Francisco-based company turned a profit last year, posting $7.31 million in net income.

Representatives for LendingClub, Morgan Stanley and Goldman Sachs declined to comment on plans for an IPO.

LendingClub's net revenue — derived from fees paid by lenders and borrowers — almost tripled last year to $98 million, according to the company's annual filing. The company's valuation reached almost $3.8 billion in April, a 63 percent jump from November, people familiar with the matter said then.

The banks and offering size for LendingClub's IPO were reported earlier by the Financial Times.