Square, the mobile payments and financial services firm cofounded by Jack Dorsey, has confidentially filed for an initial public offering, perhaps giving the interim Twitter CEO too much on his plate as he oversees Square's IPO while trying to turn around Twitter's fortunes.

Citing people familiar with the matter, Bloomberg reports that Square is working with Goldman Sachs, Morgan Stanley and J.P. Morgan Chase for the IPO. The latest report confirms what Forbes reported in June that the San Francisco-based mobile payments company was getting ready to open the company to investors under the Jumpstart Our Business Startups Act, which lets companies with annual revenue below $1 billion to secretly file an IPO.

In the past year, Square has processed around $30 billion in payments, expanding from selling the square credit card reader to businesses that cannot afford the technical equipment to accept credit card payments. It is also looking to launch a new wireless device that will allow business owners to accept payments made through Apple Pay.

However, Square's IPO complicates matters for Twitter, where Dorsey owns a majority stock of 3.6 percent. Since 2008, Dorsey has been chairman of Twitter's board and came back earlier this year as interim CEO following former chief Dick Costolo's resignation over his failure to grow Twitter's user base. Dorsey also owns a 26 percent share in Square and is the mobile payments company's biggest stockholder.

Since taking over Costolo's position, Dorsey has been increasingly active in his role as chief of the microblogging platform, meeting with smaller teams to review their products and firing Twitter's communications chief in a bid to bring in a new strategy.

However, the Square IPO is likely to take up more of Dorsey's already busy schedule, even as Twitter's board has expressed in the past that it prefers a CEO who can commit a full-time schedule to Twitter.

"I am grateful for the talented team at Square, which I will continue to lead," Dorsey said in June. "We have built a very strong company from top to bottom, and I am as committed as ever to its continued success."

In the event that Dorsey chooses Square over Twitter, the microblogging site is reportedly eyeing its current chief financial officer, Anthony Noto, formerly of Goldman Sachs, to head the firm. Another possible contender is Twitter's revenue chief Adam Bain, although some point out Noto has CEO experience and Bain does not.

Photo: Brian Solis | Flickr