The investment by JPMorgan's $1.22 billion digital growth fund would value the messaging service at more than $4 billion. That's according to the Financial Times, The New York Times and The Wall Street Journal, which cited unnamed people.
Twitter did not immediately respond to messages seeking comment. JPMorgan declined to comment.
Investors have shown keen interest in social networking services in recent months. Last month, daily coupon website Groupon raised $950 million after reportedly turning down Google's offer to purchase it for $6 billion. Facebook, which is privately held, brought in $1.5 billion in a recent round of funding engineered by Goldman Sachs Group Inc.
